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.
The various tender crops planted in Air-Pot® Tender Crop containers have had a few months of typically cool Scottish summer weather now. The tomatoes and baby corn hit the roof and have yielded some early pickings. My Air-Pot tomato plants are healthier with bigger fruits and the baby corn are producing excellent little cobs. Generally growers only expect 4-6 cobs per plant so I’ll be interested to see how many I get in an Air-Pot®.
The automatic watering system has been crucial to the success of this greenhouse and has worked brilliantly. I highly recommend the system from Tank Fed Irrigation http://www.tankfedirrigation.com The slow rate of watering works perfectly with the Air-Pot containers. I was recently away for over a week and every plant was well watered.
Another outstanding performer has been the chilli plants in 10 litre Tender Crop containers. They are along the south-facing glass and have formed dense bushes which are dripping with fruit. My chillies in 3 litre containers are paltry by comparison, as are some in another greenhouse border. The bigger container seems to give optimum amount of root run and good aeration and drainage. The 10 litre grown plants are still actively growing and flowering while the 3 litre plants are limiting themselves to ripening a few fruits.
I have installed the same drip system in the back garden. It is not timer controlled but has still made watering much simpler, especially for those tending my plants while I was away. A plastic dustbin acts as a reservoir, a tap connected to the irrigation line feeds water to about a dozen blueberry bushes and tomato plants, all in Air-Pot® containers. Even tomato plants in rather undersized 3 litre pots have done well, I think these would have dried out with normal watering. A kitchen timer is advisable as a reminder when it needs to be turned off. I have forgotten a couple of times which wasted some water but had no ill effects. It does not seem to be possible to over water an Air-Pot, the drainage is so good that once the compost is saturated excess water just runs out. My big concern about switching to container growing was always the problem of watering, so now that seems to be solved I am a convert.
High Summer is when all the hard work yields results in the vegetable garden. We opened the 50 litre Air-Pot potato towers and were delighted to find over 4 kg of perfect, early potatoes in each tower, including lots of big “bakers”, and very few tiddlers.
The same variety in the ground was later, did not yield as heavily per plant, and the tubers were smaller. So the Air-Pot towers are well worth a try, particularly if you are short of space, or just want a few extra earlies.
I did notice the compost in the middle of the tower was quite dry despite generous watering, so I will sink a short watering tube to direct some water straight to where the tubers are swelling. I will also try 4 tubers per tower rather than 3, vary their depth a bit, and experiment with feeding. Maybe bigger / better / earlier is possible? I immediately re-planted a tower with some chitted main crop potatoes, this may need some protection from frost at the end of the year, but could produce welcome new potatoes in winter. Earlies and lates from a pot standing in an unused corner seems a good return and while some strive to reduce food-miles, the distance from Air-Pot to table was all of 3 meters!
My small greenhouse is now stocked with nearly 20 Air-Pot Tender crop containers, these come in 10 litre and 14 litre sizes and are perfect for annual greenhouse plants.
My dripper irrigation system is set up with a timer to control frequency and duration of watering. The drippers are adjustable and can be set to spray which spreads the water, avoiding dry patches in the pots. There is also an automatic vent opener so the greenhouse should look after itself for a while.
I had some little cauliflower plants in modules which had over-wintered in the greenhouse, they were planted out on the plot in Spring but I had surplus plants, so as an experiment one went into a 10 litre Air-Pot.
It stayed in the greenhouse while there was space and then went outside. It grew well and now has a small but perfectly formed cauliflower ready to pick. The allotment plants are not even close to cropping, so this could be a useful way to bring on a few early plants. I will be doing further experiments, perhaps with quick heading broccoli.
I have been hearing from Gareth Cameron, an outstanding exhibition vegetable grower. It sounds like his Cumbrian garden has taken a battering from the storms & late frosts, but he has lots coming along in poly tunnels. I will be going to have a look at his onions in Air-Pot containers in the Summer, and see how his potatoes compare to mine. I think mine might be ahead at this stage. Not that it is a competition or anything.
Gareth told me about a range of five powdered plant feeds by www.dragonflyeurope.com They are made entirely from natural ingredients and are formulated specifically for different stages of growth. There is also a foliar feed and a sort of ‘compost tea’ in a sachet full of beneficial bacteria, like a pro-biotic for plants.
For control of aphids and other pesky insects he swears by Dr Brommers soap from the same distributer, with the addition of essential oils. His formula for natural organic pest control:
10 drops Lavender oil, 6 drops Peppermint oil, 1 tbs Dr Brommers soap, 3 litres water.
Well, we are into June so there should not be any more frosts here, but late May saw some wintery hail, and early June is proving to be chilly and very windy. So I am glad I kept my dwarf French beans are in the greenhouse in their large Air-Pot propagation tray. With improving weather I have now planted them out. Each plant has a mass of healthy roots. We continue to eat salad grown in Air-Pot® propagation trays, a sowing every 3 – 4 weeks is ensuring a continuous supply of leaves. An early sowing of Red Mustard Frills which was cut down to about 3 cm is growing back strongly and is providing a second picking. The Bull’s Blood beetroot in a tray gives striking red salad leaves, but I am now pulling entire plants to give the remaining plants space to develop actual beetroots. Moulin Rouge which is a type of Choi Sum oriental green was a good lettuce substitute when young is now sending up flower stems, these are a good stir-fry ingredient, so we are getting more than just a few leaves from these trays. It is nice being able to move the trays, currently at their best, right up to the patio doors where they can be seen and easily picked, while newly sown or recently cut down trays can go elsewhere until ready. The Casablanca early potatoes are stunningly healthy looking plants, perfect glossy leaves & big vigorous haulms, they seem too good to be true!
I just hope what is below ground is as good, there may be edible tubers already but I want to let the tiddlers bulk up as much as possible so am trying to be patient. They should still be much earlier than field grown potatoes in this area.
April has seen some lovely sunny weather but also some very chilly mornings, Air-Pot® grown plants which have been protected from the cold have really streaked ahead. In just a few weeks the Potato Towers seemed to have filled-up with healthy foliage, I have just earthed-up the plants by troweling in compost to the top of the container. Potatoes in the open ground are not even showing yet! The polythene cover is still ready to be pulled over at night if frost is forecast as temperatures can vary so much in Spring.
The Air-Pot propagation trays sowed with cut-and-come-again salads have been a success, the Spicy Salad mix and the Giant Red Mustard were unbelievably quick to develop in the greenhouse. Careful picking of leaves and pinching out any flowering shoots seems to work better than cutting, the depth of the trays is greater than a traditional seed tray allowing a bigger root system which should mean the plants actually do come-again. Other salads looking good are Red Frills Mustard and Moulin Rouge.
I experimented with multiplying onions known as potato onions in Air-Pot® containers, these are similar to a shallot and normally form little clusters of bulbs. I only had two precious bulbs and they have romped away from a November planting producing exceptionally vigorous plants which are about to flower, so I will soon have lots of seed to increase my stock. Apparently flowering of this strain is quite rare, clearly early planting in an Air-Pot gave them what they needed to trigger flowering. For future bulb production I will plant sets in Spring so they do not have time to flower, maybe sometimes life in an Air-Pot is too good?
The sap is rising now and there are lots more seeds to be sown and jobs to do in preparation for the growing season ahead. The trays of cut-and-come-again salad are appreciating the warmer and lighter conditions, not long until they can be grazed. I got some broad beans started in an Air-Pot® seed tray a while ago and I am pleased with their progress. Germination has been close to 100 percent in the greenhouse where they are safe from mice and cold, soon they can be planted out to give an earlier crop than the outdoor sown beans.
The potatoes in Air-Pot potato towers are putting out some leaf a couple of months ahead of potatoes in the ground, of course they need to be protected from frost so I pull over a cover at night. The transparent bubble plastic cover can be left on during cold days when it acts like a mini greenhouse. Once the shoots are a bit longer I will top up the towers to the brim effectively earthing up the plants, giving them space to produce another layer of tubers.
I fancied trying some grape vines so got hold of a white and a red type, pretty hardy varieties but in Scotland they are unlikely to crop well outdoors. So they have been planted in Air-Pot containers. Apparently once they are well established and are correctly trained and pruned they can crop well for several years, I think they will be happier for longer in Air-Pot containers than ordinary pots. They will end up in 45 litre containers which can be moved into a greenhouse in late winter / spring giving them the chance to get growing early so they have a long enough season to produce ripe grapes. Just have to wait 3 years now.
The new greenhouse has been built at the allotment & the plan is to have it full of chillies, peppers, tomatoes, aubergines, cucumber & maybe a melon by the summer. Everything will be grown in Air-Pot containers to maximise yield from what is a very small greenhouse 6′ x 6′ (1.8 x 1.8m). The root system which develops in an Air-Pot is very dense so it is crucial to keep the pots well watered. A big vine tomato on a hot day really needs to be watered twice if relying on a watering can. I cannot manage twice daily visits to the plot so have set up a drip irrigation system.
This should mean the greenhouse will be self watering for at least a few days. I have set up a water tank next to the greenhouse connected to the gutters, so it will fill with rainwater, with the fall back of using a hose if there is a prolonged dry spell. The tank I used is a salvaged cold water storage tank, the type that used to be in every loft but often goes in the skip when new systems are installed. It holds 50 gallons, sits on a platform and creates a head of pressure to feed the water lines to the plants.
I bought a 30 plant kit from www.tankfedirrigation.com, which is one of the few gravity fed systems. It seems to be pretty high quality & should last 10 years, about the same as an Air-Pot. A good feature is the adjustable water emitters which can be easily unblocked if required. The kit came with good instructions, the initial set up was straightforward & everything worked with no leaks, which is unusual for any plumbing job in my experience.
I expect to have around 15 pots in this greenhouse, each with 2 water emitters. I am sure there will be a fair amount of fine tuning to get the right amount of water where it is needed. It would be nice to know that if I am away for 3 or 4 days in the summer my plants will not go thirsty, & during longer absences if a kindly neighbour is prepared to water at least they will only need to top up the tank occasionally.
The days are lengthening and there is the occasional sunny day so I have sowed some hardy seeds, several types of cut and come again salads are in Air-Pot propagation trays in the greenhouse. Some will go under the grow light to try and bring on plants for a really early cutting.
My homemade compost mixed 4:1 with loam has been used in potato towers to get the early potatoes started. I am using the 50 litre towers which have a base and can be moved. They are in a frost free shed, with compost to about the three quarter level where the air holes stop. Above this height the Air-Pot wall has no holes which allows watering without water spurting out through the air holes. Three tubers per tower are nestled down in the compost, when leaves show the towers can go into the greenhouse and compost can be added to earth up the plants until the tower is completely full.
I generally start broad beans and early peas in troughs and lengths of guttering under glass as these seeds are very prone to rotting off in the cold, wet ground if sown direct on the plot at this time of year, and if they don’t rot mice often get them. So I have big Air-Pot seed trays filled with peas and beans, I hope these will grow well in the greenhouse and will transplant without too much of a check in the Spring.
As an experiment I have planted some shallots in Air-Pot seed trays, they are quite close planted so may not get very big but at least I know they will produce some disease free sets for planting next year if disaster strikes the main planting at the allotment. Who knows maybe they will reach a decent size as they will be in the greenhouse, and will be well fed and coddled.
It is the start of a new year and time to buy seed and plan what will grow in the garden during the coming season. Among the first things I will be sowing are onions, chillis and cut and come again salads, the hardier salads such as mustard, rocket, mizuna and beet should give some welcome fresh leaves in early spring. I hope Air-Pot seed trays will help these salads establish good strong roots so the little plants can come back after several cuttings. I have made a grow light and will provide bottom heat to nurse the early sowings through their first gloomy weeks.
One job I did do was to pot on three small blueberry bushes into 7.5 litre pots because the older bush (pictured on the left) I had in an Air-Pot container did so well last year, it put on masses of growth and should be big enough to give a decent crop this year. Because Blueberries are very particular about soil type I cannot easily grow them in the ground so they will remain in pots to fruition, I think a big container makes sense for them, I did hear that a bathtub is about right for 2 bushes, I think a big Air-pot will be better than a bathtub as they will not get root bound and they should develop well and crop quicker.
I have had a good tidy up in the greenhouse so I thought I would look at the roots of some Air-Pot grown plants. I had got my hands on some 7.5 litre Air-Pot containers in the summer so was able to try a tomato, a cucumber and a couple of capsicums. The roots of the tomato and cucumber had already rotted away but the pepper plants were still alive and the roots were quite impressive, they had completely filled the container with no sign of any circling.
The outstanding success this year was the greenhouse cucumber plant, it reached the roof and produced 2 flushes of huge, perfect cucumbers, around 8 in total. The tomato plant gave us a good amount of orange plum type fruits, and even the capsicums fruited better than my previous attempts. To improve the yield and extend the season I think the tomato and cucumber needed a bigger container such as the 10 or 14 litre Air-pot for tender crops. These are wider than the standard shape and better suited to shallow rooting plants like tomatoes and cucumbers, the 7.5 litre container seems big enough for the capsicums but I only got 4 or 5 peppers, a bit of heat early in the season might be what they need to boost the number of fruits.
Yesterday I went to a National Vegetable Society (Scottish Branch) seminar where I helped man the Air-Pot stall. The members who attended and the speakers had a truly outstanding level of expertise and knowledge about vegetable growing, and many of these expert growers had good opinions of Air-pot containers. Several people went away with Air-Pot potato towers after the presentation about growing potatoes for exhibition, I am really looking forward to seeing if I can produce a very early crop in these next year.
At the seminar I picked up a tip for ridding homemade compost of unwanted brandling worms (see previous post). Simply heap the compost into a point, the worms will migrate down from the narrow peak where it is too dry and light for them. Remove the worm free peak, then repeat until just the soggy bottom remains, full of worms which can be returned to the compost bin. This tip came from an ex-worm farmer, currently selling beetle faeces (I bought a tub). Amazing what you pick up at these events!
This week I have been busy turning a very full compost bin, giving all the partially rotted material a good mix and allowing me to get at the lovely crumbly humus at the bottom.
Next year I intend to grow quite a few plants in Air-Pot containers with some of my homemade compost in the growing medium. A homemade mix will be particularly worthwhile in big containers like the Air-Pot potato tower. Buying bags of sterile potting compost is fine for seed sowing and small containers but will be costly for the bigger containers.
I have to admit that my compost is a bit rough and twiggy. I believe this can be a particular problem when using an Air-Pot container because the growing medium must nestle into the conical shaped studs.
So I need to sieve the compost to a maximum particle size of about 20 mm. A quick rummage through my scrap pile turned up a perfect piece of metal mesh with 20 mm x 20 mm holes, which luckily just fitted on my wheelbarrow. Simply dumping compost onto the mesh was a bit messy so I made a simple wooden frame to contain the compost and hold the mesh flat.
It is an easy job to riddle the compost through with the back of a rake. The sieve catches sticks, lumps of moss, avocado pips and mango stones etcetera, which I chuck on the burn pile or back on the midden.
I am quite pleased with the dark brown refined compost, it really smells quite delicious; nutty with a spicy note. I will probably combine it with a bit of loam and grit or vermiculite, and a handful of fertiliser such as blood, fish and bone. I just need to persuade the red brandling worms to move out. Spreading the compost in the sun might discomfit them and make them seek a shady spot where I can easily gather them up?