This year I planted the potatoes a little differently than I did last year. They went into the claw foot tub as usual, but instead of just poking them down a few inches I dug out 2/3rd's of the soil and then planted the potatoes. I stored the excess soil in garbage cans to use later. When the potatoes sprouted their foliage several leaf layers above the soil, I added more soil up to just below the top leaves. When they grew more, I added more soil until they reached the top of the tub. I would then usually mulch with straw, but the foliage was so dense I couldn't adequately add it, so skipped that part this year. When the foliage died back I harvested.
I got quite a few potatoes this year, more red than whites. The main problem I'm facing when harvesting is damaging the potatoes with my shovel. Some of them got sliced in the process. When I use a fork, they got skewered. I attribute this problem to having to dig in close quarters. Of course, I also had some escapees in the process (pictured above). However, I received some great advice from a gardening cohort on how to grow potatoes when you don't have huge amounts of plantable area in the ground. Garbage cans. What a great solution; potatoes grown in a vertical garden!
Next year I'm procuring a classic style garbage can for each variety of potato I plan to plant. I'm using galvanized cans, not those flimsy plastic things made out of petroleum products. Some folk use old tires. Although it is seemingly a good way to re-purpose some of the zillions of old tires that pollute our environment, the thought of planting something I'm going to eat in a petroleum product that God knows has what nasty chemicals leaking out, doesn't sound that organically appealing.
To plant the cans, it's important to have good drainage. I'll be drilling 3-4 drain holes in the bottom of each can and then elevating them on some bricks. I'll start with a foot of soil on the bottom of each can and then plant the potatoes. As with the tubs, I'll add soil as the potatoes grow taller. You'll need to fill a couple of extra cans with soil to use later or have a tarp covered pile stashed somewhere. When the potatoes are ready to harvest, I'll simply push the cans over to spill onto tarps and pick out the potatoes. Skewering and slicing problem solved. Just you and a friend pick up the soil with the tarp and pore it back into storage.
I'm not using potting soil (way too expensive) but an organic planting mix with plenty of compost to keep it fluffy and to add nutrients. A good organic phosphorus based fertilizer mixed in such as, fish bone meal will help increase the yield.
One last tidbit of advice: urban gardeners, keep your cans well away from the sidewalk so dogs don't get tempted and pedestrians don't toss things into them you wouldn't want to eat. Even with the lids off, one never knows, as the cans will be fairly empty looking for awhile.
Come next spring's planting season, I'll let you know how this technique is working.