I experienced some different results than you, RBG, and I thought this post revival was as good a reason as any to start sifting through the photos on 2 phones and a camera, which I have been dreading for some time now. So, as an aside, thanks for inspiring me to get that done
I have 18 gallon tubs that I use for potatoes. This is the second time ever that I've grown potatoes, and last year, I planted in summer for a fall crop. Last year's results were not as good as this year's, but I was also plagued with cabbage and hornworms last fall. They decimated the plants and I don't think they ever got a fair shake. This year, things went well. Nothing got eaten by bugs or worms although I think one variety was battling early blight. All three varieties produced roughly the same amount so I'm not counting that as a negative.
Some details of how I treated them: Initial layer of soil was about 8", with the seed pieces planted about 3-4" down. I "hilled" twice by adding soil each time the plants were 8-10" above the soil line. I left as many leaves exposed as possible, but I did cut off anything that would have left the leaves on the soil. After the last hill, I mulched with hay and straw 2" deep to the top of the tub, burying the drip line at that point. I used potting soil for acid-loving plants, amended with compost and 4-6-3 organic fert initially, then just the potting soil for the hilling. They got fed compost tea every 2-3 weeks. I planted 1 tub each of "Kennebec" and "All Red," and 2 tubs of "German Butterball." 3 seed pieces per tub, pre-sprouted, and I cut out any extra eyes/sprouts. Cuts were dipped in fireplace ash (because the paper the seed came with said to) and allowed to heal for another day. Yield was roughly 1 pound of potatoes per plant (3 pounds per tub +/-). I think the biggest potatoes were about the size of a baseball, but the majority were golf ball size - plus or minus.
Here are some photos of the growing/harvesting:
All things tolled, container yield isn't that encouraging given how much it costs for certified seed and my penchant for wanting to grow everything. It is fun and interesting though, and so far everything we've grown has been extra yummy. I am going to do it again next year, and keep trying different varieties. Someday when I have more land for a garden, I can then, perhaps, devote a ground plot to the special ones that I found along the way.
I did learn that taking the old soil and using it to help fill a giant new raised bed has both pitfalls and benefits. For MONTHS in the spring I was pulling "weeds" out of the bed. They grew so big and so fast and they didn't look like the regular kind of weeds I get here... but then again, they didn't look like anything I had planted either. One day, I plucked one and a tiny potato was attached to the root! I must have pulled dozens... which means I didn't do that great a job clearing the soil from last fall's planting.
I let this one stay. I fear it has plans to swallow my house:
And this one too. My reward for this one choking my beans and squash.... tada! TPS! Not sure what I'm going to do with them yet.... but I suspect I will HAVE to plant them to see what happens!