|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.
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.
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?
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
A Peruvian White Habanero plant produced enough aromatic fruity pods to make an excellent Habanero Ketchup for which I found an excellent recipe on YouTube at: https://www.youtube.com/watch?v=HzsbMzv7ygk
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.
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.
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.
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.
Winter is over at last and the some Air-Pot grown salads started earlier this year are just beginning to yield some welcome fresh greenery, and my jewel like radishes will be ready soon.
Oriental greens, such as komatsuna and tatsoi which were sown last Autumn, are useful during this hungry gap while we wait for the summer abundance.
As I grow more crops in Air-Pot containers, particularly in the greenhouse, I am realising how useful they are for early and late produce. My early salads have been protected from the wild weather, and the quality is superb. When I grow radishes on the plot something nibbles away at the leaves making them look like shotgun pellets have blasted through them. This could be flea beetle, which attacks brassicas like radish and mustard leaves. Trays of broccoli seedlings also benefit from this protection.
I have just posted my first YouTube video – the first in a series on growing tomatoes. I hope you enjoy it and it gives some good advice.
It is still a bit early to be starting tomatoes but I thought it would be worth sowing a few to get some extra early fruit. Also I am keen to see how they do in Air-Pot containers from the outset. Plants which spend their first weeks in small Air-Pot containers don’t develop the root deformities which are inevitable in standard pots, meaning they should get the best start in life. I got great germination and have about thirty plants in a small propagation tray as well as eight in a 1 litre propagation pot. I find a really hot cupboard or propagator gets tomato seed growing in five days, then of course they immediately need good light.
Soon after germination I discarded the weakest seedlings and thinned overcrowded clusters to give the best seedlings room to grow. After four weeks, when big enough to handle, they were potted individually into 1 litre Air-Pot containers. Expensive seed was sown just one to a pot so no transplanting at all is required
It will be two months before it is warm enough for tomatoes to be set out in my greenhouse. It may be necessary to plant them in their final pots sooner and give them some protection on cold nights. The Air-Pot will keep the young plants in good condition, ready to grow on when they get the chance.
Trees have a tendency to accumulate around my garden, many of them unsightly sticks in pots at this time year. Conifers are a welcome exception, their life affirming greenery the reason so many northerners decorate homes with Christmas trees. The downside of this tradition is the piles of dead trees which litter the streets in January. To avoid adding to this waste I bought a pot grown tree which should serve to cheer our festivities for several years. Potted conifers can just about survive in a traditional pot for a few years but the lower branches tend to lose needles. Air-Pot grown trees suffer less and do better for longer, so I put my Noble Fir into a large Air-Pot container. Luckily the rootball was not too severely deformed by its confined upbringing, just a bit of spiralling of the roots which were teased out before repotting. In the Air-Pot the roots will be air-pruned as they fill the container developing into a very dense fibrous mass. Increased amounts of water and nutrients drawn up by the fine roots should support optimum top growth.
The original Air-Pot was designed primarily for tree nurseries. Air-Pot grown trees grow fast and can be kept in the pot in good condition for longer and When they are eventually planted out they establish quicker with fewer losses. So I have high hopes that my tree will become an old friend through many Christmases to come.
Here at Latititude 56º North we get just 7 hours of daylight in mid-winter, the watery grey light is the colour of Tupperware! Barely enough light to keep plants alive if they originate from lower latitudes, especially if they are being kept indoors where light comes from just one direction through a window. I want to keep some pepper plants going through these dark days so decided to rig-up a LED grow light in my house. I have been very impressed by the brightness of these lights, certainly bright enough to keep the peppers happy.
The Air-Pot propagation / salad trays which yielded the first pickings of the year, will probably give the last pickings as well. After mid-summer is when most of the oriental greens do best, I have sowed a succession of these and they are providing lots of green leaves for salads and stir-fries, they do not bolt so readily at this time of year and are quite happy outside in the cold and rain. It will be interesting to see if the salad supply can be maintained right through the winter.
After the early potatoes came out of the Air-Pot potato towers in July I decided to try to get a second crop. I was doubtful these late planted potatoes would be ready before winter but gave it a try using seed potatoes I had knocking about. The plants developed well despite being in a rather shady corner, and in late October we opened the pots to find a very decent crop of main crop Rooster potatoes. A very worthwhile way to get great yields from small spaces and something I will do again.
When clearing out the greenhouse in the Autumn it is interesting to look at what has been happening inside the Air-Pot containers. The tomato plants did well above ground and it is clear that this is due to the excellent root system which has developed. The roots have filled up the entire volume of the compost with no circling.The air-pruning of root tips in the cones (from which they cannot escape) forces the plant to continually make more roots from nearer the base of the plant. More roots which can take up more water and nutrients. We washed some of the earth away from the rootball to reveal these super-roots.
Chillies in 10 litre Air-Pot containers have been the outstanding success of the summer. These were drip watered and comfrey fed and have produced a bumper crop. Nigel’s Outdoor Chillies from realseeds.co.uk proved to be well suited to Scottish conditions. Vigorous early growth and flowering resulted in lots of big crunchy fruit, which from September they have been red and ripe.
Some other varieties such as Cayenne and Purple Haze were grown in small 3 litre containers, these produced smaller plants but the fruit has still ripened.
Faced with this abundance of Air-Pot grown chilli peppers I decided the best way to preserve them was to make hot sauce and I found a simple recipe on YouTube https://www.youtube.com/watch?v=0eX32vNExnI
Quantities are based on the amount of chillies that will pack into a 1 litre jar, this will be about 400 grams. Simply make a cut down the side of each chilli to allow the air out and the brine to get inside. Then pack the chillies into the jar, with six to eight peeled cloves of garlic. Pour in enough water to completely cover the chillies and garlic, strain out and add two teaspoons of salt, and two teaspoons of sugar. Give this a good stir to dissolve, then pour back into the jar pressing the chillies down to drive out trapped air.
Cover and leave to ferment for a week, liquefy with a blender and then cook with a chopped onion and 100ml of vinegar, until the volume has reduced by half. Once cool blend it again and you have your sauce. In sterilised jars it should keep for a year or more.
I always seem to have plants around which I do not want to throw away but which I do not have space to plant in the ground. Over the course of the season a few of these misfits were planted in Air-Pot containers, often with the intention of finding a permanent home later. But of course, some are still in pots months later. Fortunately the crocosmia bulbs and hydrangea plants are none the worse for it.
Spring onions in an Air-Pot propagation tray were left to mature, mainly because I had lots of other onions to eat. I thought I might plant them out to grow for seed production, however they are still in the tray, sturdy as a little grove of trees, apparently quite happy and about to flower in soil just 10 cm deep.
Of course successful growing in containers usually needs plentiful feeding, especially greedy crops like tomatoes. My allotment greenhouse plants were all fed exclusively on homemade comfrey feed, they thrived on this producing big heavy crops. Whereas plants in the garden greenhouse were all fed on a high quality organic feed which contains seaweed, but they are not as good as the comfrey fed plants at the allotment.
Comfrey feed is made by simply immersing a tub full of leaves in water for a few weeks, this stinky brew is then added to a can of water (about 1:5) and given to plants once or twice a week. Comfrey is easy to grow in out-of-the-way corners, borage and nettle leaves can also be thrown into the pot to steep.
A couple of baby corn plants in 14 litre Air-Pot containers have produced a modest harvest of dinky little cobs. Any kind of corn is a bit of a gamble this far north which is why I went for the quicker cropping baby corn and kept some under glass. Some plants were left outside; they have been a bit slower to develop but have still grown well.
I put three young plants in a 50 litre Air-Pot potato tower which I had handy, filling it two-thirds full of compost. After several weeks I topped it up. Maize plants throw out prop roots from the lower stem so I thought earthing-up around the stem would give the prop roots something to grow into. I did not realise the response of the plants would be to send out multiple stems. It seems earthing-up not only gave the aerial prop roots compost to grow into but also stimulated buds at the buried nodes to develop. So now the potato tower contains the original three stems, plus seven or eight subsidiary stems, It is quite a dramatic pot full, especially with the hairy tassel like flowers from all the embryonic corn cobs.
Air-Pot potato towers are designed to allow for earthing-up. The top portion does not have holes which means plants can be started with the container only partially filled. I am now wondering what other plants could benefit, I may try proper sweetcorn and black currants.