I planted a 5'x 5' bed of potatoes this year using a block planting method. On two of the corners I made "potato towers." Using hardware cloth, I made two circles, and at the base of the circles, I planted a couple of potato seeds. Over the summer, when the plant reached a height of approximately six inches, I was supposed to bury it up to its top leaves, leaving about an inch sticking out. The theory is that as the plant keeps growing to get above the soil, it will set roots every six inches or so, and at each level, there will be potatoes.
It's kind of like hilling the potatoes, in really deep hills, which, supposedly, encourages the plants to set more potatoes and for the potatoes that grow to grow bigger, and it also prevents the potatoes from getting "sun burned" when they grow too close to the surface.
The garbage can method, and the tire method, and the wooden tower method (where you planks are added as the potato grows) all work in the same way. We've tried the tire method, but it didn't work at all for us. We got a few potatoes, but nothing very impressive. We also tried using a plastic storage bin, and it did okay, but again, I wasn't terribly impressed with the results, and if the object is to grow enough for subsistence, we'd have been very hungry.
On the nanofarm, however, it is imperative to find growing methods that make the best use of space while producing the highest yields. So, I thought I'd give the vertical method of potato growing another try. This was the first year we tried hardware cloth for the tower, and I have to say, I'm pretty impressed.
At the end of the summer, I should have had two four foot tall wire-encased towers of dirt under each potato plant, but we pretty much neglected one of the towers, because we just didn't get enough compost to fill them both. I dumped a little dirt on the plant once or twice, and added some spent straw from the bunny cages once. It had one plant growing out of the side and another one growing up inside the tower. The plant on the inside died back a few weeks ago, but the other one seemed to be doing okay. We decided to harvest it today.
I found this:
It weighs just over a pound, and I'm not exagerating, not even a little. It's definitely the biggest potato I've ever grown.
There was another two pounds of spuds in the tower varying in size from about a quarter the size of this one, which to me is a fairly respectable size for a potato, to the size of a small marble. I'll probably pressure can the tiniest potatoes.
So far, we've harvested about 20 lbs of potatoes from the 25 sq feet of space, and I haven't even begun to dig, although the chickens and ducks have been doing a good job of unearthing them for me. There probably aren't a whole hell of a lot more potatoes under there, but still 1 lb of seed = 20 lbs of potatoes. Not a bad yield for my first time planting potatoes in a bed.
In final analysis, I have to say, I'm very pleased with the potato tower. I didn't even, really, take care of this one the way I should have, and it gave three pounds of potatoes. If we'd really been careful about cultivating the space and adding compost like we should have, I'm certain we would have been rewarded for our efforts.
This year's potato tower experiment has convinced me, though, that I could grow enough potatoes for my family for the entire winter in a 25 sq foot raised bed using the hardware cloth tower method ... if I make sure to fill the towers as the potatoes are growing.
Potatoes, grown in hardware cloth towers, will definitely be a staple in our garden in the future, and maybe, next year, I'll grow scarlet runner beans on the outside and potatoes on the inside to maximize my space even better ... or, as I add soil to the towers, maybe I push a few carrot seeds through the cloth, and we'll have the makings of a good stew in one tower ... just add chicken.
And speaking of, if the hens don't stay out of the potatoes next year, they might round out my stew for me.