My garden is too small for planting any reasonable quantity of potatoes, plus they need a lot of cultivation, plus they exhaust the soil - so when I saw a solution for growing a few spuds sustainably, I knew it! Mary Zemach, a local permaculture legend, figured this out.
1. Take old leaves (ideally you stashed several bag-fulls last fall when your neighbors where removing these from their lawns and gardens with enthusiastic fervor. Maybe you came by and kindly offered your place as a depository for the neatly bagged leaves. Neighbors were thrilled and delivered their bags). If you don't have leaves, look around for some other soft biomass that may be laying around - the whole idea is to convert something unwanted into something wanted - pure alchemy in fact! Straw and chunky compost will work.
2.Take a black plastic trash bag and cut off the bottom. Open it in out in a circle and lay on the ground. No soil preparation underneath is needed. In fact you can place your future potato tower on top of weeds, but ideally you cover weeds with a thick layer of newspaper to smother them. Fill the bottom portion of the bag with about 6" leaves and some soil and/or compost; fold the rest of the bag for now. The exact combination of filler mixture will vary from climate to climate, so treat this as a learning experiment - you will need to adjust amount of soil, water and work on all other variables. One thing stays constant - potatoes produce new tubers above mother tuber, that is why they take so much work if you grow them in the ground. By using tower you are going up and work with the plant!
3. Place your potato(s) in the mix - I think I will go with three per basket. Cover them and wait for emerging leaves. Keep adding leaves and soil/compost mix as your plants grow, raising the soil level and lifting the plastic bag. Your wire basket will keep the whole tower stable. When the season is over, pull up or open your tower and gently tip it. The leaves (now magically partially converted to potatoes) will spill into your garden, potatoes will come out easy and without digging and you can re-use the whole contraption next spring! You can also plant other things in the tower once it reached its height. Below is a photo of Mary's tower mid-season - it is at its full height and is also providing home for an eggplant.
Other gardening ideas from Mary: grow your horse radish in plastic perforated tubes, stashed in a wire tower filled with straw - the filler keeps the root zone cool and moist, and tubes make it easy to pull otherwise very deep root of this plant.
END OF SEASON WISDOM: (new insight) - potatoes like cool soils - ours did not produce well in the baskets because the soil was too warm - next time I will either use TIRES, or create a way to keep the soil bag shaded and cool