Prepare the seed potatoes by cutting the potato into a few 1-inch chunks. Be sure to include an "eye" on each piece. This is where the new plants will come out of.
Also be sure to not cut the pieces too big. A smaller chunk of potato helps the plant put down roots, rather than live off the stored food in a big piece.
Remember each eye will start a bunch of roots so you don't need a lot of eyes on one piece.
Let the potato chunks air dry for a day. This toughens the outer layer of the potato and helps it resist disease.
Dig some compost into an area where you will be planting the potatoes. The dirt should be loose enough for the potato to send down roots easily.
Now grab a chunk of potato with the eye pointed up and push it down into the dirt. Repeat till your done planting your potato chunks!
Next put about 7-8 inches of compost on the potatoes. Water completely. This will help it hold together. Keep the mulch damp.
As the vines start to show through the mulch you can feed it( if you want to) I sometimes use fish-emulsion once a week until the flowers open, then stop feeding.
Every time the stems grow about 6 inches mulch away! The potatoes grow at the ends of stolons. Pretty soon you'll see some tubers developing! Its very exciting!
Now its time to harvest if you enjoy new potatoes. The best part about this method of growing is that you can "steal" new potatoes, without disturbing the plant. Just move the mulch gently out of the way and snip with your fingers the new potatoes off the ends of the stolons.
Be sure to only take about 20 percent of the new potatoes at a time.You don't want to stress the poor plant!
Keep watering the plants throughout the season to keep them making new potatoes.
If you want to let the potatoes mature and get larger, stop watering them after the flowers bloom. This causes the plant to start concentrating on developing the potatoes. Then, in the fall, when the plant begins to die back, move the compost away and harvest the full-grown potatoes!! A miracle!!