Choose a sunny spot in your yard, or even on a deck, in late March. Be sure there is good drainage, as potatoes do not do well in extreme dampness. If there is risk of frost, be sure to protect your young sprouts with hay or an overnight cover to prevent plant damage.
Place a tire in your selected spot and fill it about half full of rich, damp soil.
Place 4 to 5 seed potatoes in the soil about 2 inches deep with the shoots facing upward.
Cover with a couple of inches of soil and water well.
Add another tire and more soil when the plants reach 2 to 4 inches in height.
Repeat this process until you have 3 tires stacked and continue adding soil to the emerging plants. Potatoes will be growing as you build the stack.
Harvest your potatoes by beginning with the top tire and working your way down. Young potatoes will lie toward the top, and the main crop of potatoes will be towards the bottom.