My cardboard box experiment was a failure. Here are the results:



That's right—I ended up with only a few tiny potatoes in each one.

I'm sure I was part of the problem. Even though the boxes were next to a faucet, they were in a place I don't pass through regularly and I had trouble remembering to water them. However, I definitely watered them enough to keep them alive all summer. I noticed that the box on the left, next to the plastic compost bin, had moist soil all the way to the bottom. The others had hard, crusty soil near the bottom.

I had a couple of other problems. One was I had a hard time scraping up enough good soil to "hill" the potatoes. The other was the boxes split at the seams (on the corners), so they would not hold the water I did add. For that reason alone, I would not recommend using cardboard boxes as planters to anyone else. One more thing: I had imagined the boxes would be portable. They're not; they were too heavy for me to move even they were only partly filled. Then the bottoms started rotting, and no one could move them without the soil and plants falling out.

I had high hopes for the potatoes growing in the cooler. I had gradually filled that to the top with good soil, and it was insulated from the heat. It seemed to hold water well, but it also had all the drain holes drilled in the bottom. However, as you can see, it yielded only two tiny potatoes.

Well, now I know. I might try the cooler again for tomatoes or other things that grow above ground, but I don't plan on using cardboard boxes for gardening again.