The first chills of Autumn are in the air and the tender crops are nearing the end of their growth for this year. The Maskotka tomatoes mentioned in the summer post as a super-early ripening type are still going strong, so have proved to be one of the first AND last.
Another tender crop now winding down is the Mini-Rocoto chilli, which has yielded very well. The thick fleshed orange pods are actually not so mini, the largest approach the size of golf balls or walnuts.
We have seen spectacular growth by some trees this year. Acorns sown last winter have reached 1.8m and a small avocado plant brought into the tunnel for the summer has hit the roof. A generous sized Air-Pot container really accelerates development and we will experiment further next year with more small trees, such as more avocado, fig, and apple to see how quickly we can bring them on.
Some longer established trees are also of interest are: a Pink Lady apple tree grown from a pip, which has produced beautiful fruit; and a date palm which was recently re-potted, showing a good view of the air-pruning roots. These vigorous downward pointing water seeking roots would have become severely pot bound in a conventional pot, as they circled seeking a way out.
Herbs have been giving a good return especially coriander which performed well in an Air-Pot tray staying lush for weeks before going to seed.
Botanically also a herbaceous plant, bananas are getting off to a strong start in Air-Pot containers. One veteran now planted in the ground is big as a house.
Plants in pots are actively growing now Summer is here. A Fatsia japonica which has not yet found a place to be planted in-ground has been moved around the garden for a few years and recently found its happy place in my shadiest spot under trees against a wall. This relative of ivy now has big glossy dark green leaves which look much healthier than the yellow and washed out appearance it had developed in full sun, sometimes it is better not to be in a hurry to plant out.
A varigated Hosta is also enjoying life in dappled shade with the Fatsia and the cream white of the varigated leaves seems to stay lighter in the shade. Hostas are well known to be a favourite food of slugs and snails, however they are deterred by the texture of Air-Pot containers which acts as a bit of an obstacle course for them.
The hydrangeas have put on their best ever display of big pink flowers. The biggest and best recently moved into 20 litre Air-Pot container and is growing in finely sieved homemade garden compost. I simply add plenty of water and the occasional feed.
Agapanthus from South Africa are out in a sunny spot open to full southern exposure; fairly dought tolerant they can survive quite long periods of neglect. I find an occasional dunk in a bucket of water is a good way to rehydrate their fleshy roots and keeps them happy for weeks. Mine are currently producing light blue flowers. The air-pruning effect of Air-Pot containers prevents the congested pot-bound root ball which I have seen bust open a conventional plastic pot.
The Maskotka tomatoes are cropping well and came out top in our taste comparison of early ripening tomatoes. The best performing early chilli has been Ohnivec, which is excellent sliced in vinegar, just as good as jalapeno, but earlier, more productive and hotter.
Air-Pot containers are perfect for trees such as pawpaw (Asimina triloba) which have a strong tendency to form water seeking tap roots as seedlings. The tap root will be air pruned when it reaches the base stimulating the tree to send out a mass of lateral roots. These are sensitive plants so will receive V.I.P. (Very Important Pawpaw) treatment.
Other trees benefitting from an Air-Pot start are a little lemon plant grown from a pip, an older Meyer’s Lemon which is flowering profusely (a cold-tolerant variety) and a Black Pine shooting up new growth.
Fruit bushes are proving to crop well in Air-Pot containers. A redcurrant and gooseberry in 20 litre pots are now well established with fruit forming nicely, but these are vigorous plants so will probably benefit from potting-on into the largest pot in the Garden Range after fruit as been picked. Actually given how quickly these bushes have grown they could have jumped straight into the 38 litre Extra- Large size last time they were re-potted, bigger is better for soft fruit.
I have been enjoying the super fresh rocket grown by the back door in an Air-Pot salad tray and the green multiplier onions in a 20 litre pot. These onions are a perennial which can be harvested at any time of year and propagated by simply replanting an offset. They do not produce seed (like garlic), so you have to know someone who can share them. They have been grown at my allotment site for a century, we call them Syboes in Scotland.
Lots of hardy plants are starting into growth in the garden and seed trays and seedlings are waiting on windowsills for warmer days.
The Meteor peas are now in full flower having over-wintered in the greenhouse and a pot of carrots is dense with feathery foliage. Both peas and carrots are only just being sown outdoors, so the pot-grown plants will give welcome early crops.
I am experimenting with pot grown Rhubarb and a recently lifted plant has established well in an Air-Pot container. It could probably live and crop permanently in a larger size pot, or it could just be temporarily “parked” until there is space in the ground.
A gooseberry bush lifted from the ground is also healthy and coming into leaf. Again it was in the wrong place and needs to be “parked” having self-seeded among the raspberries. It can wait in its Air-Pot container until a planned fruit patch is ready.
Longer days and higher temperatures have spurred onions and garlic into producing fresh bright green growth in the big Air-Pot raised bed. A top dressing of blood, fish and bone in Spring invigorates these over-wintered alliums.
Soon it will be time to sow cucurbits, such as squash, to jump into the raised bed as soon as the aliiums are lifted around mid-summer. An early cucumber is already flowering in a 3 litre Air-Pot but the main sowing of cucumber, squashes, courgettes etc. will not be for a few weeks. A lucky few may get to live in the new insulated Air-Pot polytunnel.
It is early days but a tray full of ‘Chico 111’ tomato seedlings is growing well on a sunny window sill. The Air-Pot seed tray is deep enough to keep these young plants growing until it is warm enough to pot them up individually in the greenhouse. This early bush variety can often produce an early crop ahead of late blight outdoors.
A blight resistant ‘Nagina’ tomato is already in a 1 litre Air-Pot container. This type can grow very tall and keep growing almost into winter. This one early plant could potentially provide lots of cuttings, saving on expensive F1 seed. As the weather warms the main sowings of tomatoes will soon fill every sunny spot. This year a new variety for me is Pommodorino del Piennolo del Vesuvio which I hope will produce the best pizza sauce. I will eventually move the smaller bush tomatoes into medium (9 litre) and the taller vine / cordon types into large (20 litre) Air-Pot containers.
Another good use for the Air-Pot trays is for growing salad leaves and a couple of trays can provide continuous pickings of lettuce, rocket, mustard, mixed leaves, etc. I also have a pot filled with French Sorrel plants, which were forked out of the ground last Autumn and kept in the greenhouse over winter. This has brought their growth forward and in addition to early salad leaves they will soon provide enough to use as a lemony spinach substitute.
A rather weather-beaten Tea Bush (Camelia sinensis) has bravely struggled through a few Scottish winters now and appears to be producing seed for the first time. Apparently it is happier given some protection in this climate so it has been potted-on and will be moved into an insulated polytunnel in the hope that this year we can grow enough tender leaf tips to brew some homegrown tea.
There is not much actively growing at this time of year, but it has been a mild winter so some cold-tolerant plants are making good growth.
Autumn sown peas have survived and thrived in large Air-Pot containers. Sweet Peas can do well over winter as well as hardy culinary varieties, if given some protection. My pot full of Meteor is about 30cm tall now and has just produced its first flower. A January sowing has just been made in gentle warmth and will go into an unheated greenhouse once germinated. These pot grown peas should give a succession of pickings. Later sowings can be the more tender second early and maincrop varieties and particularly productive are the sugar snap and mangetout types which have edible pods.
The mild winter has benefited plants which sometimes look very bedraggled after harsh weather. Evergreen ferns such as the Japanese Tassel Fern still has fresh-looking lustrous dark green fronds. Also exotics such as Agave filifera from Mexico are looking fairly unscathed by the dark days of winter.
An Air-Pot container thinly sown now with leek seed should quickly produce little grass-like plants. These do better in a potful of clean well drained potting compost than sown directly in a seed bed, where they can easily be overwhelmed by weeds. These plants should go on to become pencil thickness transplants by mid-summer and full grown leeks a year from now.
If you can provide some heat and light it is not too soon to be sowing a few tender crops such as aubergine and hotter chillies like Scotch Bonnet which need a really early start if they are to crop well before the end of summer. But it is easy to get carried away and end up surrounded by an indoor jungle of overgrown tomatoes and cucumbers by late Spring. On balance with faster growing plants I favour holding back and delaying sowings.
We have had the first blasts of wintery weather here in the U.K. so it seems high-time to finish harvesting warmth loving crops such as potatoes. The foliage of some potatoes planted back in mid-July was dying back, so I opened up the Air-Pot potato tower to find a decent crop of nice clean tubers. It is good to know this late timing can succeed, as it shows two crops from one pot is possible: March to July followed by July to November.
Surprisingly some chilli plants are hanging on and producing ripe pods in the greenhouse a yellow piripiri appears to be the most cold tolerant. There are even a few tomatoes hanging on to a battered plant in a large Air-Pot container outside the front door. Admittedly there is probably not much advantage to leaving tomatoes outside this long but it is interesting to see what is possible given a mild Autumn.
A yuzu citrus tree in a bespoke XL 50cm diameter Air-Pot container has put out lots of new growth this year after it outgrew the largest pot in the ‘Garden Range’ of Air-Pot containers. This is a useful way to keep larger plants happily growing in pots beyond the maximum standard size of Air-Pot container. A strip of wall material can be ordered to create a pot of any diameter (look for ‘Build your own pot’ in the online Air-Pot shop). I set my big pot on a small slatted wooden pallet and lined the inside of the base with landscape fabric. The good drainage provided by an Air-Pot container suits citrus very well as they resent very wet roots for lengthy periods.
A Christmas tree bought last year in a tiny pot has survived and thrived after moving into a medium sized Air-Pot container, this tree will go to spend its second December with a grown-up daughter before coming back to daddy for the remaining eleven months of the year. A veteran tree in an Extra-Large Air-Pot container will join our fesivities for about the fifth time, assuming I can lift it into the house.
As a little experiment some turmeric root has been put into small pots of compost in a very warm airing cupboard to try to get them to sprout. It might seem early to be starting a crop for next year but these rhizomes can be reluctant to get growing, by starting now they will have an entire year to produce a crop before next winter.
I have had a very good harvest of Pink Fir Apple potatoes grown in a Air-Pot potato tower. The tubers developed well throughout the depth of the container, which confirms that main crop (indeterminate) types are the way to maximise yields from these deep pots. Quick maturing ‘early’ types are also a worthwhile catch crop as shown by a pot growing from a July planting and looking good into the cool back end of the season.
Other late plantings are carrots and hardy ‘Meteor’ peas which are getting a head start making good growth during the mild Autumn weather. They may need protection in the greenhouse soon but will grow quickly after the coldest winter chills are over.
The main harvests of chillies are gathered but a favoured few plants have come indoors to finish ripening on a sunny windowsill, the habanero type ‘Rocato’ is looking particularly pretty with its drippy jewel-like pods.
Other experimental plantings which have produced fresh new foliage are some palms and ferns, the palms are in full sun and seem to appreciate the good drainage provided by the Air-Pot containers. More surprising is the good growth of ferns which are often associated with damp conditions, they do seem to prefer shade but not soggy soil as can occur in conventional pots, they actually generally need well aerated roots as much as most other plants.
Even though many have had a wet summer crops in pots still need lots of watering, especially as the plants get bigger and more thirsty. A drip irrigation system in a greenhouse can be a big help, even allowing trips away from home if connected to an automatic timer. The irrigation tubes and drippers are just about visible in some of these pictures from the greenhouse. The egg-like white aubergines are ready to eat and are a good choice in cooler climates as there is no need to wait until they fully ripen.
The tomatoes are hitting the roof and touching at the ridge to form an arch. Top varieties this year are Ferline and Crimson Plum which have been productive indoors and out. They have the advantage of being blight resistant, so even stand a chance of cropping outdoors during warm wet spells when blight destroys most outdoor tomatoes.
The big Pink Fir Apple potatoes in an Air-Pot tower are showing signs of natural dieback, suggesting the first flush of tubers will be fully developed below ground, but as a lot of fresh new haulms have appeared harvest will be delayed in the hope that the total crop will bulk up further. Meanwhile an experimental late potato planting in July is pushing up healthy growth, I doubt these will continue until Christmas as frosts will nip the foliage before then, but given a bit of protection with fleece on cold nights this might produce some Halloween potatoes.
A Chinese Golden Lotus Banana (Musella lasciocarpa) has thrived since moving into a 20 litre Air-Pot. It has produced lots of tropical looking foliage and about 15 pups. Enough to divide next year and risk planting some out in the ground where they might grow big enough to flower – if they survive a winter or two. There is always a danger that borderline tender plants like this might be killed during a hard winter outdoors so it is nice to have a productive ‘mother’ plant somewhere warm to restock outdoor plantings if required.
Garlic / Chinese Chives are growing better in an Air-Pot container than on the plot so there are plenty of succulent leaves for stir-fries and salads, and there is a good showing of pretty white flowers which are the tastiest part of the plant.
Also providing good pickings are mixed salad leaves in an Air-Pot tray. Sometimes I am not sure what leaves I am eating but they add a bit of interest to a lettuce salad and can provide an almost continuous supply if a second tray is sown to take over when the older tray is finished. Many Oriental salad leaves actually grow better in the cooler part of the year and herbs such as coriander will last all winter.
The 1.2 metre diameter ‘Mega’ Air-Pot raised bed is proving to be very productive. The investment in a large quantity of compost and manure seems to have been worthwhile, yielding a good crop of large over-wintered Japanese Onions. These are ready earlier than traditional Spring planted onions, which means there is time to immediately follow with another summer crop. I topped up the bed with a little more manure and planted four Hokkaido Squash plants which were ready in 1 litre Air-Pot propagation pots . These squashes grew well in the bed last summer but the vines rambled off 4 or 5 metres in every direction possibly wasting some of the energy which would be better directed into the fruit. This year I will stop branches about 5 leaves past each squash to try tame the vegetative growth and improve yield.
My biggest ever potato plants yet in a container are standing tall in a 50 litre Air-Pot Potato Tower. Four Pink Fir Apple tubers were planted around Easter and the haulms are reaching for the sky. Grown in the ground the long shoots of Pink Fir Apple could just be allowed to flop, but would need to be well spaced out. A few canes and a turn of string keeps them tidy in a pot. This variety is a late main crop so will continue to grow for several more weeks.The tubers should bulk up making use of the full depth of compost in these deep pots; a good way to use vertical space for maximum food production on a patio or in a small garden.
A pot full of carrots sown directly into the compost in February is providing good sized roots. They have bulked up well, perhaps because they were slightly more spaced out than previous sowings. I have also realised that carrots are a very thirsty vegetable, so have given them plenty of water. Being around to water more, due to hardly travelling anywhere during lockdown, has had some benefits!
The gooseberry bush in a pot is now dripping with red ripe grape-like fruit which have turned quite sweet, a redcurrant bush in an Air-Pot has also done well, this seems like a good year for soft fruit and berries in my garden.
There is lots of new growth now the days are getting longer. Indoors the usual tender crops such as tomatoes, cucumbers and peppers are coming along well in small Air-Pot containers, ready to set out in the greenhouse as soon as the cold nights have passed. An experimental Autumn sowing of Aquadulce Claudia hardy broad beans in a pot is looking good. Keeping them in the greenhouse through the coldest weather means the plants are well advanced compared to outdoor sowings. They flowered well and were visited by bees so pods will now be swelling.
Digging around in the greenhouse I spied what appeared to be an Avocado pip sprouting a green leaf, when carefully lifted it turned out to be a fat sweet chestnut (no idea how it got there) with a substantial tap root thrusting downwards. This type of vigorous tap root will quickly become pot bound in a conventional pot; they hit the base and are forced sideways into an ‘L’ shape and then circle endlessly seeking a way out. Of course this Chestnut went straight into an Air-Pot container which will air-prune the tap root, encouraging a more branched root system with more fine feeding roots.
Some palm trees which were recently potted-on into bigger containers proved to have well air-pruned roots. Thick succulent roots of a date palm poked out through holes in the raised base of an Air-Pot but were unable to extend further due to the drying air circulating under the pot. Another well controlled root structure was in evidence when recently repotting an agapanthus. This is in contrast to the ordinary pot it came in which had been split open by these rather thuggish roots.
Once again the Hostas are thrusting up, looking like a miniature forest. Every year they get get more vigorous and more densely jammed into the pots. Best of all they do not suffer from slug damage. We think the side of an Air-Pot is a bit of an obstacle course for the slimy pests.
The cherry trees in pots have broken bud and are showing lots of blossom, and a pip grown apple tree is going to produce its first ever blossom. If an apple results it will be interesting to see if the genetic dice-roll has been lucky. It could be delicious like the Pink Lady parent or it could be a sour like a crab apple. All the advice is not to bother growing apple cultivars from pips as they are usually unstable hybrids but this was from a pip which actually germinated inside a Pink Lady apple so I felt it deserved a chance.
Most commercial potting compost is suitable for growing in Air-Pot containers as long as the component size is small enough. If there are large lumps these may not fill the cones in the wall and roots will not grow into the cones as intended. Air pruning is achieved when roots get caught in the earth filled cones and unable to turn around they are forced to halt at the air hole. A more branched root system develops with many fine roots, rather than fewer coarse roots which can become pot bound as they circle around. Commercial potting compost is usually finely sieved and good to use straight from the bag. If using homemade garden compost it will certainly be best to pass it through a riddle or sieve to remove sticks and to break up lumps. Previously I have hurled the garden compost through a large flat piece of mesh sitting over a wheelbarrow. This works well but involves a lot of shaking, riddling and tipping aside of coarse stuff and sieving a whole heap is fairly heavy going.
A great labour saving device to make this job easier is a rotary compost sieve or ‘trommel’. I see motor driven trommels can be bought for £450 or there are YouTube videos showing cobbled together hand cranked versions using a flimsy mesh cylinder and bicycle wheel rims. My homemade version uses stiff metal mesh panels within a wooden hexagonal frame mounted on a cement mixer. Even freshly dug wet compost can be fed into the open end of the hexagon as it turns and most of the material quickly falls out through the mesh. Lumps can tumble around further breaking up and eventually the stubborn sticks, mango stones and avocado pips can be tipped out. If you do not have a handy cement mixer I am sure a simple frame with a turning crank could be devised. I used this 25mm sturdy mesh because I had a sheet to hand, the length of the trommel was determined by the 66cm width of the sheet but seeing how the compost falls out I see it is longer than necessary so I may shorten it to around 50cm. The 25mm spacing of the mesh allows even wet compost to pass without clogging, for really finely graded compost for filling small pots I may re-sieve some compost once it is drier through a finer mesh inserted in the drum.
I have quite a few trees in pots, mostly just leafless sticks at this time of year. Two cherry trees in Large Air-Pot containers have established well after they came supplied in a very small pot or with just a tiny plastic wrapped rootball. They are ready to move on to the Extra Large size with plenty of that sieved garden compost plus a generous amount of blood, fish and bonemeal. I’m hoping for a decent bowlful of cherries this year.
For the first time I will be planting a large bare rooted tree in an Air-Pot container, this is an experiment and the three metre tall James Grieve apple tree may not survive as losses from planting bare rooted trees are always high. But I know some commercial potted tree suppliers routinely establish bare rooted field grown trees in Air-Pot containers before selling on to customers. The superior root system developed after a season or so in the Air-Pot containers means almost all these trees will survive after planting out. I will try to keep this old Scottish apple variety in the pot espaliered against a wall for a season or two, and know that it should grow well once it finds a permanent home in the ground.
Now that many of the summer crops are finished there are empty pots to fill. The big raised bed made with Air-Pot wall material grew some lovely squashes and is now planted up with over-wintering onions, I planted Senshyu, Elecric and Radar in concentric circles as soon as the bed had been cleared. These onions are most easily grown from sets, I started them in modules just to break their dormancy and make some early growth before the cold weather. The small plants were then moved into the cleared raised bed and should provide early onions next year.
The extra large pot sown with carrot seed in late summer is now providing regular pickings of baby carrots, these are really just thinning to give the remaining plants space to develop but are still very welcome. Pulled while small the skin is paper thin and eaten straight away they are unbelievably crunchy.
A pot of Mizuna Greens is now a mass of healthy leafyness which is tender enough to eat raw as salad or it can be wilted in a wok at the end of a stir fry. It has been happy outdoors but I am fairly sure this would have suffered from pest damage in the ground, slugs and flea beetle seem to massacre Oriental salads when sown directly in soil. Cold weather will nip these leaves eventually but by moving under glass they will stay appetising for much longer.
Another plant which is looking good as we near the end of the year is Fatsia japonica with its glossy evergreen hand-like leaves. Now that it is in flower it is easy to see similarities with its close relative ivy. Both flower in Autumn and the fatsia is quite a handsome pot plant through the winter when most of the garden is leafless.
Capsicum pubescens are a species of chilli from high altitudes of South America which tolerate cold better than types such as the Caribbean Scotch Bonnet. These Alberto”s Locoto plants from Bolivia still have lush dark green leaves and their large glossy egg shaped fruit are continuing to turn bright red.
It is so good to reap the fruits of your labour at the season’s end, I think this year I grew my biggest ever tomato at over 400g, this Amish Paste was almost a meal in itself. A new variety which also did well is Nagina, a blight resistant plum tomato which was soon hitting the roof grown in the greenhouse in Air-Pot containers and has proved to be good as a salad tomato or cooked into sauce. It is an expensive F1 seed so just two seeds were started extra early which meant there was plenty of time to remove side shoots and root them in order to have lots of bonus plants later in the season. Because they are blight resistant they can be gown outside as well as under glass, and because they all grew from just two seeds there is enough seed left to produce plants for years to come.
The peppers and chillies are still ripening, perhaps the favourites this year are Bolsa de Dulce (Bags of Sweetness) which can easily be de-seeded by cutting out the stem and shaking out the seeds, leaving a hollow round shaped chilli perfect for stuffing with cream cheese, or just steeping in a sweet vinegar. A huge number of Bolsa de Dulce ripened early in the season even on small plants grown in 1 litre Air-Pot prop. pots. For bigger hotter chillies Ohnivec has been a star performer producing masses of long fleshy pods which will probably mostly be dehydrated and powdered.
The raised bed made from a length of Air-Pot wall material has grown a nice crop of Hokkaido squash which are safely in storage now that frosts are threatening. The plants were extremely vigorous grown in this deep bed. A selection of winter hardy Japanese onions have been rooting and sprouting in modules ready to jump into the raised bed as soon as the squash plants are cleared away. This was such an easy way to quickly create a deep bed of lovely rich compost I look forward to seeing how different crops grow in this.
A tree fern which was bought as a short length of bare trunk last year has rooted well in an Air-Pot and produced a good spray of fronds. The trunk was kept moist by frequent hosings as a lot of water is absorbed through the trunk which is actually formed from roots, but the base prefers not to be very wet so the good drainage of the Air-Pot container has suited it well as it allows excess water to escape.
In August some forgotten potatoes stored in a corner of a shed were rediscovered covered in long sprouts and roots.As an experiment these were stuck in an Air-Pot Potato Tower that had been recently emptied of an early potato crop. I think the sprouts on these may have got overlong but some decent plants have emerged so it will be interesting to see if they can produce a crop so late in the season. They will need to move into the greenhouse soon and be protected with fleece on cold nights, hopefully they will prove to be less tender than generally thought after all wild potatoes grow high in the Andes.
Around a month ago a big Air-Pot container of carrots sown in January was opened up; the perfect roots weighed in at 3kg. Sowing in a container is a good way to produce a clean crop of early carrots as carrot root flies skim the soil surface and do not find carrots raised up in a big pot. The same pot was immediately sown with another crop of carrots and should yield a late crop. At both ends of the year it is easy to tie a clear polythene cover over the pot creating a mini-greenhouse and extending the active growing season. The 25cm depth of soil in the Extra Large Air-Pot give plenty of space for developing roots.
Chillies are beginning to ripen and I made a batch of Thai style sweet dipping sauce; mainly using the Jamaican Red Hot chillies which have produced lots of their distinctive mushroom shaped pods, even in a tiny 1 litre Air-Pot ‘prop’ pot. I also included some very early ripening Yellow Piripiri. The dipping sauce used 800g windfall apples (cores and pips included) boiled for an hour in 1 litre of water and strained through a jelly bag overnight to yield 500ml liquor. This high pectin liquid will thicken up 1 kg sugar to a good dipping sauce consistency, when heated to jam setting temperature. Before heating with the sugar I added about 200g chillies to the apple liquid in a pan together with a couple of tablespoons each of soy sauce, fish sauce, vinegar, lemon juice plus a few shallots, garlic and ginger.
The Air-Pot wall material is normally sold cut to precise dimensions to suit specific diameter plastic bases, and is simply wrapped around these bases to build the pots which range in size from about 10cm diameter to the largest at around 40cm. This range of sizes suit nearly all the usual pot plant requirements from seedlings to quite large shrubs and saplings, but sometimes a truly huge container is needed and the Air-Pot wall material can be used to to make these mega pots too; they will just lack the ready-made plastic base. I made a wooden platform out of a cut-down pallet to provide a base for a 50cm diameter Air-Pot, this large pot was needed for a Yuzu citrus tree which has put on a lot of growth. The air-pot.com garden website now includes an option to select a large diameter and height under the heading “Build your own container”, the wall material will then be cut to suit.
I reckon my 50cm diameter pot-on-a-pallet will still just about be moveable by two people possibly by sliding poles or bearers through the pallet like a forklift but it will be a sweat, any larger than this and I think the pot will be a permanent fixture. Perhaps that azalea on the patio growing in a disintegrating half barrel would benefit from a larger container, the old barrel could be stripped away and a length of Air-Pot wall wrapped around with space for some fresh compost?
Another way to use the wall material is to set the large bottomless container directly onto earth, roots may go down into the soil below but if it is never going to be moved this does not matter. By creating this large container it is possible to build up a huge depth of really good quality compost and manure, effectively you have a instant raised bed. We used 40cm high wall material wrapped around to make a circular bed 1.2m in diameter and filled it with half a bulk bag of compost plus some farmyard manure.
The pumpkin plants which were set into this bed have grown at an amazing rate, far outperforming plants set into the ground with what I thought was a good amount of compost at each planting position. I have heard of pumpkins doing well growing directly on a well rotted compost heap, I guess the Air-Pot raised bed is a sort of super compost heap and we are hoping for a good crop of little Hokkaido Squash / Pumpkin.
As it was quite a big investment buying in the compost I envisage using it for several years, quite intensively topping up between crops to refresh to soil and maintain fertility. Planning ahead I imagine that the great depth of loose friable earth might be perfect for carrots which will be raised up safe from low-flying carrot root fly. The good drainage might also be good for onions.
It is nearly warm enough now for northern growers to move tender plants out into the greenhouse and look forward to cucumbers, peppers and ripe tomatoes. But anyone who has had a lot of potted plants to tend through a summer knows that watering can be a bit of a chore, especially when plants like tomatoes get big and thirsty. Drip irrigation systems work really well with Air-Pot containers, if you can raise a barrel or tank near your potted plants the drippers can be gravity fed and controlled by a battery powered timer.
This is convenient if you do not have a mains water supply or just do not want to trail high pressure pipes around your garden. A large tank on a 60cm high platform beside my greenhouse feeds 20 or 30 pots for 10 – 14 days which is truly liberating. If you are setting up this type of low pressure system it is important to get the correct type of timer, many use a diaphragm valve which can only open if water pushes through at mains pressure. But the cheaper simple designs have a ball valve which opens and closes as the ball turns through 90 degrees, the type with a clear circular screw cover costs about £15 and is sold under several brand names including Kingfisher. The timer screws directly onto the thread of a garden tap and it is worth fixing this type of tap to a stake right in your greenhouse. It is then a fairly simple plumbing job to run some flexible plastic 15mm (1/2 inch) pipe between your tank and the tap. Most dripper systems will then connect to the standard garden hose click connection at the outflow end of the timer.
Usually a short length of 15mm garden hose acts as a manifold with several lines of the small diameter irrigation pipe running from puncture connections into the rubber hose. After a bit of adjustment of the drip rates it should then be possible to leave your plants for as long as the reservoir lasts.
We are expecting a mid-May cold snap here in the U.K. so my potatoes at the plot have had earth mounded up over the young shoots to protect them, but the early planted Air-Pot potato tower already has big plants about to flower, luckily the clear bubble plastic stills fits around the pot and plants. With a bit of fleece on top this should mean the extra-early crop stays snug.
Two cherry trees which had tiny root balls when I bought them two years ago have established well in their Air-Pot containers and have blossomed for the first time this year. Commercial growers do get good crops from container grown cherry trees so it will be exciting to see how these do.
The “Kordia” variety can grow several metres tall so may outgrow even the biggest pot but the smaller growing “Van” is meant to be well suited to container growing. The container carrot experiment continues, the carrots in the 50 litre Air-Pot look to be appreciating the deep soil, and two little “Long Tom” pots we made from Air-Pot wall material offcuts are bravely thrusting down in their bespoke deep pots.
Two other plantings which are just bursting with heathy growth are my favourite variegated hosta grown from a small offset and a tray thickly planted with Spring Onions which will provide welcome early season greenery.
Many people are spending time at home and experiencing difficulties getting supplies from the shops at the moment so it is especially worthwhile having some way to grow your own. A couple of pots planted with Spring bulbs can really lift the spirits, tulips and grape hyacinths have provided a succession of long-lasting colour which have occupied a prime spot by the front door when at their best.
The experimental extra early planting of potatoes appears to be successful, the shoots are showing above the soil in the Air-Pot potato tower, these plants should crop a month or so before any planted in the ground. Despite some frosty mornings the shoots are undamaged protected by the wrap of heavy duty horticultural bubble plastic which creates a mini poly tunnel around the pot.
About the fastest pickings from a Spring sowing of any crop are rocket and radish, these do well in an Air-Pot tray in a greenhouse where they crop sooner and stay in much better condition than when sown on the plot. A sowing of rocket made a couple of weeks ago should yield some leaves in another week and continue to produce into summer; this variety named “Speedy” has lived up to its name. One of the foods which for many is a real store cupboard staple is tinned tomatoes, a way to get the equivalent of crates of tinned toms is to grow your own and bottle or freeze them. Tomato seeds can be sown now, after comparing growing in bags, in the greenhouse soil and in conventional pots, Air-Pot containers have proved to be the best for me. The taste of these bottles of sunshine is fantastic and so useful in soups, sauces, and on pizza and pasta.
Various members of the onion family are putting on nice clean growth now, a pot of chives has awoken after its winter dormancy. It has been happy in this large pot for years now only needing an annual top-up of compost and the occasional feed. Small pots planted with Elephant Garlic and French Potato Onions (similar to shallots) have been given a good start in 1 litre prop. pots. These will be planted in the ground soon and should be ready to lift soon after mid-summer. Finally a sedum / Ice Plant which is commonly grown as an ornamental has produced some fresh new growth, surprisingly these are edible and are especially crunchy and succulent in salad now when leaves are young.
Northern gardeners will be seeing signs of growth now that the winter is nearly over. With some forward planning the Air-Pot containers which were full of summer crops all those months ago can be useful during this quiet time .
I have some iris, tulips and muscari bulbs coming to life which will give some colour, and little Walking Onions which will be good for salads. These onions (a.k.a. Egytptian or Tree Onions) produce small bulblets similar to little onion sets high on the flower stalk. These can be planted in the Autumn to provide a big pot full of Spring green onions. Elephant Garlic is another edible bulb which I have in Air-Pot containers. The 1 litre Prop Pots are perfect to get them off to a good start prior to planting out on the plot as the roots do not get congested, as they do in a conventional pot.
Christmas trees in pots stand a good chance of surviving until next festive season if they are well watered. Surprisingly conifer roots are actively growing now and many Christmas Trees sold in pots have had their roots hacked about, so watering and feeding will be crucial until they have recovered. My tree is now in an Extra Large Air-Pot and has been our Christmas companion for four years.
Potatoes can be planted now if you are prepared to protect shoots from frost. Three tubers in a 50 litre Air-Pot Potato Tower can produce several kilograms of extra early potatoes in a greenhouse. This year as an experiment one Potato Tower has been wrapped with sturdy bubble wrap to create an individual mini greenhouse and to ward off hard frosts which might penetrate the soil.
The tomatoes and peppers have all done well in Air-Pot containers but are now nearly all finished. Maskotka is an early ripening sprawling type of cherry tomato which looked good on the patio as well as providing good eating.
The yellow piripiri was the most productive of the chilli varieties, it is an accidental cross between a red piripiri and some unknown father.
A batch of hot sauce made from a mix of peppers and chillies has just gone into bottles and is tasting good. This sauce is a Sriracha style, which means it was fermented with lots of garlic, and the heat is down to family friendly levels; a warming condiment for the winter ahead.
Raspberry plants do not generally grow well in pots long term, but some Autumn fruiting canes which are temporarily in an Air-Pot container have provided quite a few bonus berries. It might even be possible to keep them fruiting for longer by moving into the greenhouse. Now the tomatoes are cleared out there are a few things which might extend their cropping season by coming under cover.
Colder weather is threatening some of the more tender plants such as the lemon grass, which was grown from seed this year. It has formed a good clump in an Air-Pot and is big enough to provide some leaves for flavouring curries. To get the tender inner stems which are the most flavoursome it needs to continue growing into next year. So the pot will be moved into frost-free quarters for the winter.
A pot full of Garlic Chives is dividing and flowering well after being rescued from an overgrown veg patch. Most alliums seem to thrive in the free draining conditions provided by an Air-Pot. Garlic Chives can actually bulk up to the size of baby leeks when they are happy, so potentially they can be more than just a garnish, and be used in stir-fries or as a filling for dumplings.
As the season is well advanced now it is satisfying to see good growth on plants which were potted-on into generous sized Air-Pot containers earlier this year. Two plants I wanted for their striking foliage are well on the way to becoming dramatic specimens. An Agave filamentosa has formed a neat rosette of variegated spears and a Phormium is developing an interesting stripy bronze fan, both of these will be exciting shapes and colours to have around the garden, especially in winter when there is little leafiness or colour.
A little collection of potted Canna Lily have all thrown up dense thickets of stems; moving them into bigger pots has resulted in vigorous multiplying shoots and lots of blooms. Usually Canna are grown from rhizomes, but a few seed saved last year and sown in February have formed many shoots and surprisingly have flowered after just a few months.
A young olive tree started in a 1 litre Air-Pot has doubled in size since being moved into a 3 litre earlier this year and has a good sturdy shape with dark green healthy looking leaves. Another much older olive tree recently moved into an Extra-Large 38 litre Air-Pot has produced a huge number of flowers for a container grown tree. This veteran plant seems determined to produce olives this year but I fear it will soon run out of summer, so ripe olives are unlikely. Good to see it attempting to procreate though.
Another tree trying to fruit is a citrus called Yuzu, apparently this is grown in Japan where winters can be cold so perhaps ripe fruit in Scotland is possible.
A late sowing of New Zealand Spinach produced little plants which were set in a large Air-Pot in late July. By late August the plants had filled the pot and provided enough greenery for a good amount of spinach and made a paneer curry. It is continuing to grow fast and a week later is ready to pick again. This is a tender plant so it will be interesting to see how well it can grow into the cooler end of the season.
July and August is when lots of the crops in pots start to yield good pickings. The thing I am most excited about is the amount of carrots produced in one 20 litre Air-Pot (3.2kg / 7lb). The seed was sown in Spring in a shed, which meant the soil temperature was warmer and drier; once past the early vulnerable stage the pot was left outside and well watered. I did not even thin the seedlings which would have given each root room to grow bigger. They seemed to reach a useful size despite the overcrowding and best of all the carrots were absolutely perfect with no carrot root fly damage or forked roots. I have immediately followed this success with a late sowing and in future will aim for a succession of carrot pots.
The runner beans in a pot are looking good and producing pods. Many beanstalks can grow huge and require substantial supports, which is awkward in a pot and liable to blow over, so I selected a dwarf variety named Hestia which has been very well behaved reaching only 60cm in height. About a dozen plants in a large Air-Pot with a few sticks for support have been covered in pretty red and white flowers for weeks and will now give plenty of beans for the kitchen. It is easy to end up with a glut of runners and as they are not something I love enough to freeze it is quite a relief to just have a potful rather than a wigwam load.
There is so much fresh growth on the Air-Pot herbs I thought it would be good to preserve some as a herb salt, I gathered a big bowlful of mixed herbs; oregano, chives, sage, rosemary, lovage, tarragon plus some chilli, celery, lemon zest, spring onion, seaweed and garlic granules. This was all dried, ground and blended with salt to make a tasty flavour enhancer.
Once again the hydrangeas on the doorstep are a mass of pink, they are several years old and are now thriving in the 20 litre size Air-Pot. They could be potted-on into the 38 litre extra large size but they then become rather heavy to move, It is nice being able to easily shift the pots into a prominent position when they are at their best, I find the 20 litre (large) is most useful when juggling pots, the 38 litre (extra large) good as a final home. Sometimes you have to concede that a plant is just too big to contain, my banana plant grew so quickly in a series of Air-Pot containers that eventually it outgrew the extra large size and was planted outdoors in the ground, it is now over 3 metres tall and has survived a Scottish winter.
The Air-Pot garden is growing fast now we have long days and warmer temperatures. The mange tout pea Shiraz have proved to be well suited to container growing. They were easy to keep neatly trained onto their tipi and stayed at a manageable height of about 1 metre. Next I am going to try Sugar Snap peas.
The mixed pot of spinach and kale provided a long period of useful greens and was pretty enough to have prominently on display, the Red Russian kale variety has very ornamental frilly leaves. These good looking kales are something to sow now to plant out at the end of summer as they are hardy enough to grow on into the winter.
There has been lots of potting-on to do of various perennial plants which are going to stay in containers long term. Some plants which do not need moving into bigger pots quite yet still need a bit of attention. Compost levels settle over time in any container and it is well worth taking the opportunity to top-dress. I remove any moss and mould from the surface and press down firmly around the edge, this makes space for about 5cm of fresh compost and a sprinkling of chicken manure pellets.
Before and after of a small apple tree that I grew from a pip. The second picture shows the top-dressed pot with the Air-Pot container correctly filled to near the rim.
The Bulgarian Giant leeks which were sown thinly directly into an Air-Pot in winter have now been planted out on the plot, they were considerably fatter than the grass-like scraps I have planted some years.
The greenhouse cucumber plants have gone into their final pots, I have one in a 20 litre and another in a 9 litre just to see how this affects yield and growth. I am trying the variety Carmen this year after seeing that it wins most of the top prizes at vegetable growing contests.
Now that there is more light and warmth, plants that were sown when the world seemed deep frozen are really putting on lush new growth. An experiment to try to produce a steady supply of veg from just a few pots is looking good and we have a cluster of five Air-Pot containers bursting with healthy foliage. A couple of Air-Pot potato towers have been planted with early and main crop varieties; these had an early start in a bright frost-free shed, so should be ready to harvest soon.They will then be immediately replanted with a follow on crop.
In the three large 20 litre Air-Pot containers are: a mixed planting of spinach and kale, mange tout peas clambering up canes, and early maturing carrots. The spinach and kale combo is ready for picking now and will provide a few super fresh leaves every morning, giving fruit smoothies a vitamin boost. They will crop for many weeks.
A selection of seedlings are coming along on windowsills and in the greenhouse so that when the plants currently in the large pots have finished there are plants ready to fill the gaps. Dwarf beans, tomatoes and chillies are possible replacement crops. More kale is also on hand in a small seed tray.
I have started some leeks in an Air-Pot seed tray which are very sturdy and ready to plant out into the ground. The usual advice is to plant out when the plants are about the thickness of a pencil, mine are fat Sharpie Magic Markers so clearly happy.
One litre Air-Pot propagation pots have proved useful for starting off a crate exhibition onions and some broccoli plants. I was pleased to find a plastic carrier tray free from the Ikea houseplant department that is perfect for six prop pots. A small wick made from a strip of capillary mat poked through the pot base is a very easy way to keep six pots watered from below.
If you are an optimist you might dare to hope that the coldest days of winter are past. There are certainly more daylight hours, so if you can provide a bit of warmth and protection it is time to get a few plants off to an early start. I have sown some radish, and a salad rocket named Va-va-voom, indoors in Air-Pot seed trays, and then moved them to an unheated greenhouse now they have germinated. So soon we should be eating the first salad crops of the year.
Some Air-Pot potato towers have been half filled with compost and planted with chitted tubers. I have put them in a frost-free shed and as shoots emerge earth will be added to cover them. When the pots are full and the leaves are showing above ground, they will go into a greenhouse and watering tubes made from plastic bottles installed. This will allow thorough watering right into the core of the pot. I am hoping for really useful quantities of potatoes from a small area. Plenty of water and nutrients should ensure good harvests and we will be trying for two crops, one after the other in the same pots. I have high hopes for the superb Double Strength Dalefoot Compost which forms the bulk of the potato growing medium.This is a peat-free organic product made from sheep’s wool and bracken and contains a high level of long lasting nutrients.
I have planted out some garlic on the plot that was started in one litre Air-Pot propagation pots. Protection from the worst of the winter wet and cold has produced heathy young plants, that are definitely looking much better than my usual bedraggled Autumn planted ones.
When garlic and shallots are planted in normal pots or modules the roots quickly become congested, so it was good to see the roots were nicely dispersed through the compost in the Air-Pot containers.
A very mild end of the year has meant the last of the tomatoes and chillies have only just been picked and are overlapping with some early sowing for next year. Various bulbs like shallots and tulips have been planted in pots ready to push forth; in fact some green shoots are already showing. But the main event at this time of year is sowing of onion seed. It may seem early to start onion but I have managed to get some seed from prize-winning strains of heavy onions and to stand a chance of growing into really heavy bulbs they need an early start. I don’t expect to break any records but I know the heaviest onion and leek at the last Harrogate Flower Show were grown in Air-Pot containers, so I am keen to see how big I can grow.
Only moderate heat is needed to get onion and leek seed germinated and once growing they can tolerate quite cool conditions, what the young plants do need is high light levels. A lot more than we have naturally during the gloomy short winter days we are experiencing, so I have dusted off a couple of fluorescent tube fittings for the plants. It is well worth rigging up a well lit sowing station and this set-up is not expensive, I had a couple of salvaged three foot long tube fittings and bought Gro-Lux T5 tubes which emit the wavelength of light needed for plant growth. A simple reflector can be made by glueing aluminium foil to hardboard then the whole contraption needs to be suspended over the seed trays. Using two chains attached to overhead hooks allows the height to be adjusted, the light should be as close to the plants as possible. A big piece of silver Mylar can be draped over the fitting (I used a survival poncho) hanging down both sides of the growing area to create a mini grow tent. A length of cord between the chains can be strung across to form a sort of “clothes-line” for the Mylar. This maintains a space between the Mylar and the light fitting. It is probably better not to have the reflective sheet directly wrapping over the back of the light just in case this causes overheating. My single 30 Watt tube generates a gentle heat which the plants enjoy, but never enclose any light fitting which generates a lot of heat.
The onion plants are getting 24 hour a day light for now, once they are well established and potted-up individually a timer will give a more natural day / night cycle. Germination in the small Air-Pot trays has been very good and I feel the roots will develop well in these for quite a while, but I know the top growers separate plants into individual pots soon after germination. So the best plants will be potted-on individually, but many others will stay hugger-mugger in their trays until they can be planted in the ground. After onions are moved-on of course a warm brightly lit space can be useful for getting a succession of seedlings off to a good start, such as Spring sowings of chillies, peppers, squashes and tomatoes.
I am pleased to see that my Christmas tree in an Extra-Large Air-Pot has survived another year and is pressing up at the glass at the back of the house keen to come inside for the Festive Season, this will be its forth year with us.
The end of the growing season seems to be extending later than I’ve ever known; after a few cool spells we have had pretty mild conditions. I still have ripe raspberries, I even have ripe outdoor tomatoes here in Scotland in mid November. In previous years I’ve known tomatoes to freeze solid in mid October. Lots of the chillies are still ripening including an accidental cross which has produced lots of attractive hot yellow pods. I saved seeds from a typical red podded piri-piri chilli plant a couple of years ago, but the plant which grew from that seed last year was a bit off type, and seed saved from that plant has now produced pods completely the wrong colour.
But it is a great grower with bigger pods than its Grandma, so I made a batch of piri-piri sauce which was excellent on chicken wings. I expect the original true Portuguese piri-piri plant crossed with some yellow podded chilli in the greenhouse such as Bulgarian Carrot. I like the very erect tall habit of the new plant, which comes from the piri-piri genes, and the big pod is much easier to de-seed than the little piri-piri ones. It will be interesting to see how the next generation turns out.
Talking of chilli seed, I did a little viability test of some saved seed, mainly to check the quality of the seed, some of which was rather old, but with an idea that I might get a few plants established extra early. I put a few seeds into folded moist paper towel, in a plastic container in the airing cupboard. After just four days the Nigel’s Outdoors chilli seeds are the first to germinate. As they have proved so keen to get growing, and they are usually about my earliest to ripen, I will get them into soil and hope for super precocious ripe pods.Thinking ahead to next year spurred me to do some Autumn planting of bulbs. After clearing most of the greenhouse plants out I planted up some of the bigger vacated pots with tulips and muscari (grape hyacinth), I look forward to these providing a bit of Spring colour.
Also, a lot of garlic cloves and shallot bulbs have been started in 1 litre Air-Pot propagation pots. Many people start these straight into the ground but I have had problems on the plot with rot over winter, so I will try starting in pots, and will move them under glass during wet spells. Eschalote Grise the prized French shallot has completely failed previously when outside through a Scottish winter, the good drainage in the pots should give these fickle French alliums a better chance.
The tomatoes and peppers have loved the hot summer this year.and have been ripening since June for me. The first to ripen were quick maturing types like Stupice, in medium sized pots. In large pots the main crop of heavy producing types has been giving big yields through September into October. Montello a small oval salad tomatoe has been prolific, the best beefsteak Pantano di Romanesco. Amish Paste has provided lots of passata for freezing and bottling, and now I am picking De Colgar which is an exceptionally long keeping storage, or hanging tomato.
People often ask which size of Air-Pot is best for growing tomatoes and based on my results I think the large 20 litre gives best results. The plants are bigger with more space around them for light to penetrate and air to circulate. The medium 9 litre size can be useful for the lower determinate types and early fruiting plants, which can be cleared out of the greenhouse later in the season.
A sweet pepper named Cabanero was my biggest capsicum of the season. An odd shaped chilli which came to me labelled Jamaican Red Hot has indeed been hot and red on one plant, but yellow on another. They all tasted good and went into a batch of chilli jam made to my favourite recipe which includes onion, garlic and fish sauce. As usual I grew so many chilli plants that I ran out of space so most chillies stayed in small 3 litre pots, by way of contrast up at Air-Pot HQ in the big poly tunnel a Carolina Reaper was grown in a medium 9 litre pot and produced 100 pods. These are the hottest in the world so should produce enough heat for several lifetimes.
I have been impressed with the amount of cucumbers a couple of Air-Pot containers can produce. Enough to eat loads in salads, make endless gazpacho soup and also pickle in vinegar.
Previously I have bought the very expensive F1 hybrid seeds and put one plant in a 20 litre Air-Pot. Sometimes several flushes of beautiful cucumbers result, but if the one or two precious plants succumb to some ailment all is lost.
This year I sowed lots of cheap Polish ridge type cucumber seed and planted three in a pot. They are in the greenhouse scrambling up a trellis and seem more robust than the thin skinned all-female English types. Admittedly they are small (about 15cm) and are a bit prickly but the yield is huge and staggered, and the prickles rub off easily. Some plants are probably not as productive as others but that does not matter when there are several plants in a pot. So lots in a pot will be my method in the future.
The yield has been good from an Air-Pot potato tower that has been on the patio after an early start in the greenhouse. Rather than open it early and risk a lot of the tubers still being very small it has been left until well into July. Three Casablanca tubers planted in a pot have produced 3.5 kg which is more than I get per plant when grown in the ground. Three plants at the plot would generally produce 3 kg & take up an area about 1 metre square, whereas the potato tower has only a 42cm diameter. So with four potato towers fitting into one square metre small spaces can be very productive. The key to success has been plenty of water.
From the early season to this point in high summer there has been a lot of potting-on and this post is about filling Air-Pot containers, together with some observations and tips based on my experience of using them.
Once the pots are properly assembled, ideally the right way up and not inside out, it is time to fill with compost / potting mix. Something water retentive that is not too free draining is good. It is very important to pack the growing medium into the container firmly, without leaving pockets of loose soil or voids. This is so water does not find quick routes to gush out of holes before it can be absorbed. Also the best development of air-pruned outward pointing roots can only be achieved if soil is filling the cones.
I have found the small 1 litre prop pots are particularly easy to under fill, perhaps because there is simply less weight of compost to compress downwards. I have often lifted a small pot to see large voids, sometimes with a slug in there leering out at me.
So now I use a round ended trowel to jab downwards and outwards. Initially loosely fill the pot about half way. The trowel can be used to jab down onto the base and into the corners. Then using the back of the trowel sideways press soil into the cones. Then the pot is filled right to the top, tamped down and the trowel again used to press soil sideways.
If you are moving a small plant into a larger container the initial partial fill and poking with the trowel is still the way to pack earth well into the bottom of the pot. After setting the small rootball in place the space around is filled and again well tamped down,; this can be done by lifting and dropping a short distance onto a solid surface, and the trowel used to work soil into space and cones. Finally I work around the very top pressing down the earth with thumbs to make sure water cannot easily sneak down through loose earth at the outside edge to a hole.
I find it helpful to insert a strip of capillary matting up through the base to act as a wick, especially in small pots which might be packed onto a large tray. This just means water can be absorbed from below if necessary. This is not how Air-Pot containers are designed to be used but together with top watering I find it works well in my grow tent and greenhouse for annuals, like tomatoes and chillies.
The weather has been cold this Spring, so crops in pots which can be given a bit of protection have a big head start on plants outside.The broad beans sown in an Air-Pot tray and germinated in the heat, then kept in an unheated greenhouse have done well.
The roots seemed nice and bushy when the young plants were transplanted, lots were poking out the bottom of the tray and were clearly air-pruned.
Once they reached about 15cm in height they were teased apart and planted on the plot, I’m pretty sure beans sown in the cold wet ground would have rotted or been eaten by mice.
The potatoes plants in an Air-Pot potato tower are showing above the soil and are now ready to be earthed-up. The pots were in an unheated greenhouse during the really cold weather but are now outside. The temperature overnight recently has been dropping down to 1 degree C, so the plants have had plastic bags over them, which seems to be stopping the shoots getting nipped by the cold.
Indoors the chilli plants are a good height now and mostly starting to flower, so as soon as the weather warms up they will be ready to start fruiting through the summer in the greenhouse.
The new year is still quiet on the growing front, mostly bare stems in the garden but even these can be attractive. The red stems of dogwood bushes can look stunning when the winter sun hits them. They look better if most of the stems are reduced in length before buds break into leaf though, this encourages dense bushy growth over the summer and lots of new red stems to enjoy next winter. These prunings can be stuck into earth to root, I have had about five growing in a large Air-Pot container for a couple of years and they are getting quite well branched and bushy now, next winter when a few more stems have developed I expect quite a fiery display.
I started some chilli plants at the end of last year and they are now going into 1 litre Air-Pot propagation pots, I am hoping these will be far enough advanced to use as display plants on Air-Pot stands at garden shows later in the year. Air-Pot is going to Chelsea Flower Show (22nd – 26th May) for the first time so some top class plants will be needed to dress the stand. If the young chilli plants are not ready I have managed to over-winter some of last year’s chilli plants. Pictured are a couple of Pimientos de Padrón, a little recently sown one and a survivor from last year which is already flowering, fingers crossed for some early pods.
There has been a lot of house plant tending going on of late during the cold winter weather. I was given a cutting of Monstera deliciosa (Swiss Cheese Plant) which I am trying to root. It is a variegated strain (actually more speckled) which means it is not as strong growing as the normal green type, it is planted in a little Air-Pot and is holding its own though looking a little droopy, I hope the aerated soil in the pot will be what it needs to get well rooted without rotting. it is touch and go at the moment, but I am really rooting for it (groan)! As this plant matures it will develop very thick aerial roots, which wave around looking for tree trunks to grab. Because of this unusual type of root I will be watching with interest to see how it grows in an Air-Pot. It is possible that air-pruning completely fails to occur and that roots simply thrust out through the holes in which case it will go into a normal pot.
Autumnal abundance is very satisfying but when you cannot eat your pickings fast enough you need to put produce by for the winter. An easy option is to freeze crops but I have a small freezer and prefer not to rely entirely on the freezer. So bottled tomatoes and chilli jam are a store cupboard staple for me.
I have a collection of preserving jars which I use for tomatoes, mostly the clip top type, these are excellent as there is no need to tighten the lid on a hot jar as with the screw top jars, heated air just hisses out. You do need to get hold of new rubber sealing rings if the existing ones looks at all worn, but a cheap rubber ring is a small price to pay for a litre or so lovely homegrown goodness ready to use in the middle of winter. My method is to peel and pack tomatoes into a clean jar pressing down so there is no air in the jar, or fill with a passata or sauce. I then put into an oven on the lowest setting for about an hour. When the contents are just showing a hint of bubbling it is hot enough and you can allow to cool, I have to nudge the setting of the oven up a tiny bit for 10-15 mins to reach the bubbling stage. Too hot too quickly and the tomatoes will boil with messy results. Once cool test that the lid is held on by a vacuum, unclip wire and lift by the glass lid, it should stay firmly in place.
Chilli jam is something I have a real taste for, it goes well with cheese on crackers and in sandwiches. Nigella Lawson has a good recipe based on jam sugar and peppers, but as I have a lot of apples I like to make an apple jelly which then has chilli added.
1.5kg – 2kg apples, chopped and put in a big pan, skins and cores included. Add just enough water to nearly cover the apple and simmer for an hour, mashing a few times to produce a smooth pulp.
When this has slightly cooled ladle into a jelly bag over a pan or jug. Do not press pulp but allow liquid to gravity drip for several hours, I find this produces a litre of clear apple liquor. If this liquor were to be heated up with 1 kg jam sugar or ordinary sugar plus a sachet of pectin it will set into an apple jelly on cooling, but I want to spice it up.
Get 6 or 7 jams jars clean and ready to fill, check lids, dry jars and lids in the oven.
Heat up the approximately 1 litre of apple liquor and add finely chopped chillies to taste, simmer for a few minutes to soften chillies. I used 12 fresh Aji Limon chillies and included seeds (about 100g), also a juice of half a lemon, some dried chilli powder can also be added now if desired. Next add the 1 kg sugar plus a sachet of pectin or 1 kg jam sugar. Heat and stir until sugar has dissolved and it is nearly boiling. Turn off heat and allow to cool somewhat before ladling into jars, it is very important that it is not put into jars very hot or all the chopped chilli will rise to the top. After about half an hour off the heat the side of the pan should be comfortable to touch and the jelly just beginning to thicken yet still be easy to pour and ladle, a jam funnel is very helpful or just transfer to a Pyrex jug then pour into jars. Tighten lids.
Another variation used the same basic quantities but started by frying in a large pan; 150 grams shallots, 150g red sweet pepper, 150g mixed red chilli (I included some habanero), 3 cloves garlic, 1 tbsp ginger until, all very finely chopped, fry for a few minutes until softened. Then add 2 tsp sesame oil and 2 tbsp fish sauce, and 50 ml wine vinegar.
Thereafter as before, to the shallot mixture in the pan add the 1 litre apple liquor and the 1kg sugar plus pectin, heat and jar once semi-cooled. This is a South East Asian inspired concoction, the fish sauce might sound a bit weird but it adds an umami yummyness, and the sweet peppers and shallot thicken and colour the jam nicely.
Chillies are always are fairly late to ripen in the Scottish climate even in a greenhouse, many types don’t ripen until October or later, but quite a lot of mine are ready now in early September. As usual I grew too many varieties to give them large pots, so most have been in 3 litre containers. The best performing varieties so far have been Aji Limon, Jamaican Red Hot and Rocato.
Aji Limon has very hot pods with a citrus tang and just four pods were sufficient to make several bottles of spicy yellow tomato ketchup with banana. There are dozens more on the plant so a big batch of yellow chilli jam is in the pipeline, if it works well I’ll post the recipe. This year the Aji Limon has been exceptionally good with really big fruit quite early.
The Jamaican Red Hot has also been early, not quite such a heavy cropper as the Aji Limon but a little goes a long way. I made a delicious dip with this chilli. Simply roast one with a sweet red pepper and chunks of courgette (I used nearly 1 kg courgette) and some unpeeled garlic cloves tossed in a little oil. After roasting for half an hour or so de-seed the chilli and pepper and peel the blistered skin off if it is very blackened, squeeze the creamy roasted garlic out of the skins, then mix everything together in a blender and season. Mix with some sour cream, scoop up with tortilla chips and enjoy, this is great way to use up courgette if you have a glut.
The Rocato chilli is absolutely dripping with lovely looking red pods, a huge number for such a small plant. I have not used any of these yet as I just enjoy looking at it, the foliage is exceptionally healthy looking and I think would be a perfect kitchen window sill plant as it is very attractive and fairly compact. A bit like a spreading bonsai tree but with big red fruit you can eat.
Some chilli plants have remained in one litre pots but even in these little containers they are producing well. Various cayenne types are ripening in these pots, perhaps the most impressive is an unknown type which I know simply as Turkey, because someone sent me seed they had come across while in Turkey. One little plant has about 25 pods, so a couple of these could provide 50 or so, that is about a years supply if you use one a week. It is a thin walled type which should dry easily meaning they would keep well for a long time, hung in a string perhaps. Self-sufficiency in chillies from just a couple of one litre pots is pretty good growing I reckon.
The summer sun and warmth mean plants are growing apace and in the greenhouse the tomatoes are roof height. Once again the drip irrigation system, controlled by a timer, is working well and a few main crop tomatoes are ripe already.
What has proved very worthwhile are the early ripening tomato varieties in medium sized pots (9 litre). Though a bit small for a tomato plant they are quite adequate for smallish varieties, which are yielding around three trusses of super early fruit. Most surprisingly, fruit are ripening even on the plants that were cast out of the greenhouse in June. The earliest were Stupice followed by Bloody Butcher , Sub-Arctic Plenty and Glacier. This last variety is actually growing quite tall outside against a wall, with five trusses of fruit forming.
I am incredibly excited by the growth of my banana which was recently moved from a medium to an Extra Large Air-Pot. This started the season with one or two leaves but now looks like a proper tree with a real spray of exotic looking foliage, AND pups have formed! Four little offsets have sprung up around the main truck so this looks set to be a little banana grove in a pot.
I’m also rather pleased with my onion in a pot just because it is so perfect.
The crops-in-pots are mostly still growing apace but not quite ready to harvest. There are plenty of green tomatoes, some of them rather strange shapes, but not many ripe yet.
I am pleased with my onions and leeks in Air-Pot containers, they are bigger in these pots than similarly treated plants in the ground. Giant veg growers produce monster Air-Pot grown onions and this year Mark Shepherd is quietly confident of a world record.
Flowers are being produced in abundance, my agapanthus has filled out nicely and thrown up flower stems for the first time. It split its previous pot and seems to be much better now those vigorous roots are air-pruned.
My hydrangeas have put on a good display despite having been in the same rather small pots for three years. One edible that has just started to yield useful crops are the blueberries, and the mixture of varieties should continue to ripen right through August. The Air-Pot grown bushes have been in large containers since the beginning of the year and look set to crop very well. For the first time some will have to be preserved.
A pair of blackbirds have been helping themselves a bit too freely so nets have had to be deployed.
Even though we are well into June the weather has been wet, windy and cool at times. I am glad the tender plants such as squashes are still in pots in the greenhouse. I find many of the tenderest plants stay in good condition in a 1 litre propagation Air-Pot for a long time without getting potbound.
Sweetcorn barely ripens in a typical Scottish summer so getting plants to a good size early in the summer in the greenhouse really helps them along, The roots continually improve due to the air-pruning. The same is true for sweet potato, chillies and tomato.
Sweet peas have provided a really welcome bit of colour and sweet scent, they are blooming happily in a medium Air-Pot which means I can move it easily now it is in flower.
A Hosta which was divided a year ago has demonstrated the difference between Air-Pot growing verses a ceramic planter. The plant was split in two, one half went back in original pot the other into an Air-Pot of similar volume. Both had the same compost and growing conditions, the half in the Air-Pot now has twice the foliage and ten times the flowers.
An avocado I grew from a stone gathered in Madeira has produced massive healthy looking leaves, could we possibly produce a Scottish avocado fruit in a few years?
Even though we are still early in the growing season and frost is still possible in Scotland in May I am pleased to have harvested my first early potatoes. These were grown in an Air-Pot potato tower which I planted up in February and kept in an unheated greenhouse. Mid May is a good couple of weeks better than last year when we harvested at the very end the month. I know a second planting is possible in these containers but I thought I would try Sweet Potato for a change, this will be a real long shot in Scotland but it would be a great way to use the potato tower; super-early potato followed by Sweet Potato through the warmest months.
I have been getting good results using Air-Pot salad / seed trays. The broad beans germinated really well in an 8 litre tray, with no rotting as often occurs in the cold ground. I found the roots were easy to tease apart when the plants are about 15 cm tall and one tray gave enough plants to fill a 3 metre row with some spares.
An early sowing of radish has produced absolutely perfect little radishes which are being selectively picked to leave remaining plants space to bulk up, but the early thinings are so delicious the rest will not be around for long. A lovely clean crop with no slug damage or holes in the leaves.
The other pot I am using a lot at this time of year is the 1 litre propagation pot. These are currently filling up with assorted peppers, tomatoes, cucumbers and sweetcorn. The sweet potato plants have also been kept in them and are now ready to go into to 50 litre potato tower. Quite a jump; 1 litre to 50 litre, but that is an advantage of Air-Pot containers, there is no need for small increments in pot size, the roots will fill the entire volume of compost.
The worst of the winter is past, just about all the stored vegetables are eaten and there is not much to pick in the garden. This time of year used to be known as the Hungry Gap. Extra early crops are especially welcome as they shorten this gap, which is why I try to get a few potatoes ready a little earlier every year. Last year we opened an Air-Pot potato tower at the end of May and got a useful crop. This year I’m hoping to have some ready even earlier. The plants are already well grown in the greenhouse and should survive as long as horticultural fleece is thrown over them on cold nights.
Some ornamental perennials are coming to life including hostas in pots, I was amazed at the solid mass of roots of the old plant I saw when re-potting and dividing last year. After just one season the roots of the re-potted hostas had already completely filled the new pots and were following the pot walls in layers. So, a prime candidate to benefit from the air-pruning achieved in an Air-Pot.
Along with other vigorous rooted plants, like agapanthus, canna and banana, I want to see if air-pruning keeps them happier for longer in a pot. It seems logical that terminating the growth of roots by air-pruning, leading to more branched roots, is better than allowing endless circling and the roots growing layer upon layer around the side or base of a conventional pot. A couple of canna in little 3 litre Air-Pot did well last year and apparently these flower better when they are not over-potted, so they will stay in these for another year.Likewise the agapanthus is being contained by its Air-Pot, this had actually burst its old pot, the new leaf is looking lush. We will see how both these flower this season.
Also lush and pristine is the new growth of the chives, unlike plants which cope with constrained roots, alliums seem to respond well to rich soil and a generous root run and they like good drainage. So I’ve put a little self-seeded clump into a big Air-Pot, lovely Spring greenery close at hand by the back door and hopefully a good show of purple pom-poms this summer.
It is time to think ahead to the coming growing season and I have been moving some plants on to bigger containers. The blueberry plants put on a huge amount of growth last year and when opening up containers the roots have clearly filled their old pots.
Most will go on to the biggest Air-Pot containers, either Extra Large pots, or Potato Towers. With lots of ericaceous compost the plants should be happy for several years. All they will need is occasional removal of a old stems and lots of ericaceous feed. Blueberries are definitely one of the most financially worthwhile crops and unless your soil is naturally acid they will always struggle in the ground.
Another plant which has appreciated potting-on is a Carolina Reaper chilli which was looking a bit sickly in a 1 litre Air-Pot. Since going into a 3 litre pot just after Christmas it has put on some lovely glossy new growth and is covered in flowers.
This is the hottest chilli in the world so if it crops well I’ll probably have enough heat to keep the northern hemisphere warm next winter.
The winter beetroot experiment continues, this was just a fun winter planting to see how big a beetroot can grow in a 1 litre pot. The plants were kept in a grow tent under lights. The leaves are looking really healthy and the roots are swelling nicely, so they should yield a few super early beets soon.
Other early season plantings are onions, leeks and salads in trays, and potatoes in the big 50 litre Air-Pot potato towers; these can be kept in the greenhouse with fleece over the young shoots during cold nights. My stored potatoes are nearly finished so the sooner the super-early container grown ones are ready the better. Last year we had some at the end of May, I am hoping to have some by mid-May this year.
Things have slowed down in the garden, the greenhouse is clear of all the annuals and the pots mostly stored for next year, except for some chilli plants which apparently can over winter if kept in a frost free shed. They are looking good so far, I think partly due to the good drainage and aeration of the soil in the Air-Pot containers which avoids soil staying too wet.
A couple of Jerusalem Artichokes which I stuck in a pot in Springtime, I found had produced a nice little clutch of tubers. This was a very easy crop to grow and harvest, I simply opened the container in a wheelbarrow and picked out the crop, I understand it can be hard digging out every last piece if they are in the ground so this is a good way to stop them becoming a permanent fixture in the garden. The same is true of horseradish which yielded nice roots in a pot, I just wish I had done the same with my mint!
Just to liven up the winter months I decided to try and grow some beetroot in 1 litre Air-Pot propagation pots in my new grow tent under lights. Because the tent is inside the house which is a dry heated environment I really wanted the pots to be able to draw up water from below rather than rely on hand watering from the top. This is not normally possible with an Air-Pot due to the raised base unless you dunk the pot in quite deep water, and 2 or 3 cm of water will always remain in the tray or saucer below the base, this is not desirable as roots will grow into standing water. So I threaded a strip of capillary matting through holes in the base leaving two tails dangling down, this means that if I pour a shallow puddle of water into a tray it is quickly drawn up the wick into the compost and no water remains below. I find this keeps the compost in the pot well wetted right down to the bottom and I do not have to frequently lift pots to check they are moist enough. The plants look healthy and I already had a little picking of leaves to eat, very nice they were in a saag alloo curry.
Last year I had great chilli crops in Air-Pot containers, mainly of a variety sold to me as Nigel’s Outdoors, so I was inspired to try more types. This year I have had success with Fresno, which appears to be identical to Nigel’s Outdoors. Other good performers have been Cayenne, Bulgarian Carrot and Hungarian Hot Wax, along with Aji Benito and Piri Piri, which had good early ripe pods.I was pleasantly surprised that Caribbean Antillaise and Komodo Dragon did well because these are Capsicum chinense, varieties which generally need a long hot growing season. Too many chilli plants crammed into limited greenhouse space meant many did not get potted on soon enough, but even in the 1 litre Air-Pot prop-pot I was impressed that plants grew well and fruited despite being somewhat “bonsaied”. The optimum Air-Pot container for most chillies grown as annuals is the small 3 litre size, but very vigorous types and overwintered plants can benefit from a bigger pot. The cool tolerant Rocoto chillies (Capsicum pubescens) will go into the 9 litre medium pots next year if they survive the winter; apparently they can grow into quite substantial bushes over a few years.
I am resolved to grow fewer plants of the best performing varieties and improve my growing methods, give them more space to flourish, pot-on sooner, and perhaps spread reflective foil on the staging, to boost light levels. However it will be hard to resist trying a few more new varieties, and my 2017 chilli list is already lengthening.
As we approach the end of the growing season, the star performer in terms of size achieved from a seed sown this Spring is a banana plant.
The rate of growth has been amazing, it quickly outgrew a small propagation Air-Pot and the 3 litre size. I noticed the very vigorous fleshy roots tended to thrust out through holes in the base more than is usual with other species, they were determinedly seeking expansion room. When these roots were air-pruned by the Air-Pot container the overall root development benefitted. Foolishly I left the banana on moist earth for a couple of weeks in July, allowing the roots to bridge the air space at the bottom and delve down into the greenhouse border.
Luckily I was able to lift it with roots intact and coil them into a bigger pot. This was a good demonstration of how roots can grow in air if the humidity is high enough.
Other very vigorous rooted plants that I will be interested to try in Air-Pot containers are Agapanthus, Canna and Hosta, these plants seem to crowd resentfully against the side of a normal plant pot forming layers of root instead of being dispersed through the entire volume of compost. When I bought a Blue Storm Agapanthus recently the roots had actually split the pot open!
Finally, a random experiment which I look forward to unearthing is Turmeric grown from a shop bought root. I don’t know if it is particularly vigorous rooted but looks strikingly similar to a banana and is doing well, so here is a picture.
As the end of Summer approaches the tomato harvest is at its peak. All the plants have grown fantastically well in a mixture of medium and large Air-Pot containers. The super early types which do not grow very tall were in medium sized pots and produced ripe fruit from June. Behind the earlies are the taller, later ripening varieties which are now producing well in large pots.
The only difficulty has been the plants are too big, the vine / cordon types are all trained up to the ridge of the roof suggesting a super root system has developed. I am not complaining but perhaps next year will train and prune to keep the plants lower so I don’t have to duck under them. Growing in alternative containers such as grow bags or conventional pots would have constrained the growth somewhat I’m sure.
When I grew in the greenhouse border by this is the time of year my tomato plants would sicken and yellow. I am not sure what caused this; deficiency, fungus, bug or disease. But growing in pots rather than in tired old soil has cured the problem, and using Air-Pot containers together with automatic drip irrigation has worked well. Healthier plants which grow bigger and keep cropping for longer is a good result and it will be interesting to see just how long they will keep ripening into the Autumn.
Summer continues to be typically North Atlantic here in Scotland; cool, cloudy and damp so the greenhouse is invaluable for good crops of heat loving plants. Apparently growing under glass is the equivalent of growing 500 miles nearer the equator. Peppers and tomatoes are doing well, as are the greenhouse cucumbers (Emilie F1 all-female variety), all in Air-Pot containers. I also started outdoor (ridge) cucumbers and gherkins some of which have been planted in the ground, but others which stayed in the greenhouse in pots are much bigger and are yielding nice little fruits already. I believe outdoor cucumbers should not be allowed to flower near the all-female greenhouse types in case the male pollen turns the females bitter! So two gherkin plants have been banished to a mini polythene greenhouse where they can scramble up canes flowering promiscuously without fear of tainting the delicate ladies. The front of the plastic greenhouse can be rolled up allowing air and bees to circulate, and the front zipped down at night when it turns chilly.
I already have a jar of gherkins in brine starting to ferment and expect to have enough gherkins for many more, the fermenting in brine method gives a lovely tangy taste like the Polish “Krakus” dill cucumbers.
I blanched the gherkins, put them into the jar with garlic, chilli and herbs, then poured over hot brine (3 tbs salt per litre), after two weeks the cloudiness of the ferment should clear and they are ready to eat.
I’ve just finished the first batch of jam of the year. I used all the red currants from an Air-Pot grown bush, this plant grew from a pruning which had been stuck in the ground as a row marker a couple of years ago. Surprisingly it rooted, so to give it a good start in life it was moved into an Air-Pot where it has fruited well this year despite being a young plant. I was able to move it into the greenhouse when the fruit started to ripen to keep it safe from birds.
The blueberry plants are about to start cropping, these are especially worthwhile as they are expensive to buy and continue for many weeks.
Gooseberries are also looking good with plenty of fruit, so far all the soft fruit in Air-Pot containers has thrived. The raspberry plants in pots are not fruiting yet as they are too young and I am still experimenting with types, pruning and size of pot. But anyone wanting to get the best from soft fruit in containers should certainly give it a go in an Air-Pot.
It is heartwarming to see the healthy state of this unusual citrus plant in an Air-Pot container. Citrus can be tricky to grow, so I have always resisted the temptation to get the more common types. Yuzu is one of the most cold hardy citruses so I thought it was worth a try. It is thought to have originated as a wild cross between the Far Eastern varieties Ichang Lemon and Mandarin, and is highly valued in Japan. The fruit is thick skinned and full of large seeds, but the small amount of juice from the fruit is intensely lemony, and the flavour survives cooking well. The thick zest is also a useful ingredient.
My plant (from Plants 4 Presents) is grafted onto the roots of a very hardy citrus relative Poncirus trifoliata. It coped with winter in an unheated greenhouse in Scotland and since being potted into an Air-Pot has shot out lots of new growth. The Air-Pot container filled with gritty compost ensures good drainage. It can go outside in the summer and eventually will stay outside permanently , perhaps with a wrap of horticultural fleece during exceptionally cold spells.
It feels like the garden is sprinting ahead and we are lagging behind with sowing, planting and weeding. The early plantings in the Air-Pot potato towers have really appreciated being in the poly tunnel, they have been earthed-up and will yield a June crop. The Air-Pot blueberries have burst into flower and are getting plenty of water from the gravity fed irrigation system, I will give generous ericaceous feed and they will all go into bigger pots this year. Ultimately they will all be in an Extra Large Air-Pot where they should be happy for years. I will then need to get the hang of rooting baby blueberry cuttings (tricky)!
The sweet peas have rocketed up their bamboo tipi which is covered in healthy growth ready to give an early summer display.
My cherished multiplier onions in Air-Pot containers are also thriving, they are ahead of the plot grown ones and safe from diseases. A reassuring back-up when trying to increase a precious strain.
My latest video in the How to Grow series is now live on You Tube. It tells you everything you need to know about how to grow great crops of perfect, disease free organic potatoes, in Air-Pot Potato Towers.