|Just discovered in my pantry.|
You can get a jump on growing potatoes by starting them indoors about six weeks before planting outside. Because potatoes only need soil that is about 50F degrees, they can be planted earlier than many other vegetables. A good time to begin the process for most areas is February and for colder areas you can start in March.
Potatoes are not typically grown from seed. New plants come from pieces of whole potatoes. Those gnarly sprouts growing in the dark on your shelf are the beginning of a new potato plant. When you buy "seed potatoes" you're not buying seeds, but rather a chunk of potato that as one or more eyes on it. The eyes are the small depressions that dot every potato. It's from these depressions that the sprouts develop.
The process of forcing potatoes to sprout is called chitting. When you chit a potato, you control the sprouting and prepare the chitted piece for planting. You could just pop a whole potato in the ground and wait for it to grow, but through the controlled chitting you can get five, six, or a dozen plants from a single potato.
For chitting, start with the potato that you'd like to grow. Many potatoes in the supermarket are sprayed with chemicals to inhibit sprouting so store-bought potatoes won't produce the best results. Certified organic potatoes or potatoes saved from your harvest last year are better. You don't need to wait until the potato has started to sprout; a fresh, firm specimen is good.
|Cut pieces with good eyes on each.|
Identify the eyes and cut the potato into smaller pieces with two or three distinct eyes on each. An important step is to callous the cut side. Place the potato on a clean, dry surface in a darkened area for two or three days with the cut side exposed to the air so it can dry. This helps prevent disease and allows the potato to secrete a natural fungicide. If you plant a cut piece without callousing the open surface, that piece is likely to rot long before a new plant emerges.
|Potato pieces after callousing.|
When the forgotten potato in your cupboard sprouts it's because of the warm dark conditions. Those white growths are weak and not best for growing into new plants. We want thick, healthy green and purple sprouts from our eyes. To get good ones, the calloused pieces need exposure to some natural light. Find a cool sheltered location with a window in your utility room, library, garage, kitchen, or anywhere the pieces are exposed to occasional indirect light. Place them in a clean, dry container like a cardboard egg carton, with the cut side down and the eyes facing up. Then sit back and wait. You don't need to water them or do any other typical gardening activity.
Calloused potato pieces resting in a nice, cool, lighted area should have sprouts up to an inch long in four to six weeks. That's chitting. If the potato piece as many sprouts, you can brush off the smaller ones just as you would thin out overgrown areas of your garden. When you have a couple thick, sturdy, stubby growths on each piece, you're done chitting. At that point they're ready to plant outside.
You could go through the same callousing process later in the season and plant the unchitted pieces directly in the ground, but there's no guarantee they'll grow. If you plant pieces that have already sprouted, you know the spud has a good start, will grow faster, and can be stronger and more productive than unchitted brethren.
|Planting chitted potatoes.|
When the soil is 50F degrees or warmer in March or April, put the sprouted pieces in the planting bed. Completely cover the sprouts with soil. In a surprisingly short time they'll burst through the surface. Chitted seed potatoes grow much faster than unchitted pieces.
I'll talk more about growing potatoes in days ahead. You can also read my blog "I Say Potato, You Say Potato" from October 21, 2010, to see the results of my harvest last year.