I was reorganizing my cupboard the other day, and found a couple of potatoes that were definitely beyond edible. As I was getting ready to toss them in the compost pile and hope they'd eventually break down, I suddenly thought, "Hey, maybe I could plant these!" So I broke out my favorite gardening book and got to work. I figure, if they grow, great! If they don't, I've not lost anything.
I broke the sprouts off the potatoes, then cut them into pieces, making sure each piece had at least one eye, then back in the pantry they went for 2 days to let the cuts dry.
Since potatoes are root vegetables, they need lots of underground space. To make this happen, but still allow the vine to be above ground, they need to be planted in hills, and as they grow so does the mound. They're great for container gardens, and some people plant them in old tires to help contain the dirt. I'm using a cardboard box -- it'll break down in the soil eventually, but in the meantime it'll make a great enclosure.*
Bury the potatoes 3 inches deep, then cover the plant with soil as it grows.
*This would work as a biodegradable compost bin, too. Make sure you remove all the tape and packing labels.