Ages ago I built a strawberry wall from car tyres on Gardener’s World, it worked well for years till I needed the space for grapes. I recently made a new version. The main advantages of a wall over growing in the same bit of ground-space is more plants thus bigger crops, and longer season with those on the sunny side ripening earlier and the shady side late. The downside is of course the effort to make it, more watering, with tyres slugs became a problem as too many inaccessible places and they took a lot of compost initially and when re-filling. I have been growing strawberries on trial in many sized containers and the optimum size has been small buckets. You can fruit a plant in as small a container as a metallised plastic coffee bag, which conveniently can be hung up, however this and pots up to a litre or so need interminable amounts of watering, and regular feeding.
The larger the pot the better the crop and the less often watering and feeding is required, bigger is always better but a small bucket apiece has proved optimum, so I now use many of these for my forced crops under cover where they hang in the warmth and away from many pests.
Almost exactly the same size are the much cheaper large black ‘pots’ which some supermarkets sell, these are the plastic vases cut flowers came in. I get 8 for a quid, and sometimes thanks to e-numeracy. If these vases are to be used as pots they must have several holes making in the bottom for drainage, the plastic is thin and brittle, still it melts or cuts easily with a sharp blade. Anyway these buckets have proved excellent for many crops and especially for strawberries under cover and outdoors. But as I am running out of protected space in my current fruit cage I built a wall in the corner of my old fruit cage which I can easily re-net. This is working fine but aligning the wall to face the sun has resulted in that side sagging slightly with a pronounced lean. I do not think it is likely to fall unassisted but if you are copying then beware as obviously this is a potential risk for toddlers and pets.
The lean is because the pots soften on one side in very hot sun and not on the shady side thus a North South alignment would probably end up balanced. Anyway it is a quick job to unpack and remake the wall if necessary and my temporary alternative is a couple of braces. (I am waiting till the plants flower then I am going to rearrange and replace some vases).
Making a strawberry wall. You need a load of identical small bucket size tubs/pots, each with two drainage holes opposite each other in the bottom. A flat level surface. Some lath or similar for horizontal slats to spread the load evenly. Some short stout canes bits of lath to peg slats in place in pots. Fresh new plants or strong runners, one per pot. Several bags of good potting compost, preferably peat free of course, this should be additionally enriched with bone-meal as it is to be in use three years before the plant is replaced.
To ensure a flat level surface I also used some strong gutter sections with the first slats of lath set on these, flat level concrete or gravel would do fine. The first and second tier of pots were doubled up as they were thought flimsy, I now consider triple might be better, and still cheap enough. Or just don’t go to four tiers, two are no problem, three just require sensible construction, four has proved prone to developing a lean needing props or rebuilding but it should be possible to build five or higher if you build carefully with tripling or stronger pots.
It is important to fill each (doubled up ) pot to the brim and with one plant in the middle.
These are stood edge to edge on the first pair of slats which have a space left between them.
A second pair of slats are placed on the rims of the first tier of pots, spaced either side of the plants and set inside the outer edge of their rims. Pegs are pushed into the compost in the pots at either end to prevent these slats moving. The second tier of (doubled up) pots, one less in total number, are set on those slats, edge to edge but offset by half a pot ie the centre and the plant in each pot in a tier should end up directly over the junction of those pots in the tier below. It is important to set each pot so the pair of drainage holes drip into the pots on each side below, ie the holes in a tier of pots should end up all aligned along the row.
Another pair of slats are set either side of the second tier plants and pegged then the third tier pots set. The third tier I used single pots and now think they should have been doubled as well. The fourth has no extra weight above so single skinned pots are quite sufficient.
As a safety measure I have set some metal braces in case my children knock the wall over before I rebuild and reset it and advise anyone with young children or pets to do likewise, or just build only a couple of tiers high. Strawberry plants grow large, the pots have a taper so there is a fair gap just above each plant and the leaves and flower trusses grow and push out on either side.
Watering is essential, regularly, uniformly and often. Liquid feeding is not much needed the first year with good compost but will be in the next two before the plants and compost are replaced. (Miffy ones can be replaced anytime in minutes.)
Tips; netting or other measures may be necessary to stop birds robbing you, remove all runners as soon as seen, remove poorly shaped fruits while small then the remainder swell more, remove any rotters before they spread.