After planting about 2-3 seed potatoes per tire and stacking them three tires high throughout the season, my end yield from this experiment was about 1 1/2-5 pounds of potato. This seemed to depend a lot on the variety. The russets were by far the best performer, followed by the Yukon Golds. The fingerlings were the least prolific, but the tastiest.
I decided to continue growing potatoes in tires again this year because I still had all these recycled tires laying about and I also didn’t have the cash to plant lovely fruiting shrubs there, yet. Last year I never watered the tires, so I have tried to give them water after several dry days. I started a small pile of potatoes on the side of the house in the ground to compare the two yields.
I won’t be living in this house come Fall, so I won’t be able to compare the yields between these two methods. But judging from their growth now, my money is actually on the tire method. It is only the beginning of June and they are huge! I could add a fourth tire, but don’t want to get that high. I have kept a better eye on adding more dirt as the greens reach 4″. In most cases, they get about 8-10″ high before I managed to add dirt, but that is better than my progress last year.
The in-ground potatoes are looking good as well, but they take up so much more space. I would guess they span about 2′ x 3′ and are only piled up about a foot. The tire method takes up about 2′ around and can get as high as 4′ or so. Last year the bottom tire was full, second tire was okay, and third was pretty empty. That said though, I still think I got more potatoes from that method than taking up a similar amount of space in the ground.
The tires definitely look ugly for the first couple months. However, the greens are exploding off the top which helps hide the ugly black tires. They are also starting to bloom, which creates this lovely flowering border between our patio and the garden beyond.
The biggest negative about this method is the idea that the tires would leech in chemicals. I haven’t seen any hard evidence to the fact yet, but I am certainly keeping my eyes peeled for good research. Until then, I think I will continue with this method. I just might tuck them into a less-exposed corner of the garden at some point, so they are not so unsightly during those first couple months.