Potatoes are one of the first food crops you can plant in spring. Like peas, spinach, and onion sets, they are planted as soon as the ground is dry enough to dig. If your garden is slow to thaw, don’t worry. As long as you get the crop planted four weeks before your last frost, it should do well. To start your potato patch, buy “certified” seed potatoes, which have been inspected to assure they are disease-free. Don’t plant potatoes purchased from food markets—they are not reliable for use as seed potatoes because they have been sprayed to retard sprouting.
Encourage Sprouting
Pre-sprout seed potatoes before you put them in the ground. Exposing them to light encourages them to form nubs of growing shoots from the eyes (each eye is a dormant bud). Plants treated by “chitting,” as this process is called, root quickly and mature earlier than those without sprouts. Chitting is simple: Just spread the potatoes in a sunny indoor place for two to three weeks before planting.
Cut & Dry
Cutting removes the dominance of the eyes grouped at one end of the potato and encourages all of them to sprout. About a week before planting time, cut each large seed potato into pieces weighing about three or four ounces with one to two eyes each. Spread the piece out in a single layer for a few days. The dried flesh is less likely to rot than raw cut surfaces once planted out in the cold, wet soil typical of an early-spring garden. Why not plant a whole potato? Because the many eyes on a large potato will grow into a multi-stemmed plant that bears many small potatoes.
Prepare a Furrow
Potatoes like loose, well-drained soil. Wait until the soil has dried enough to be workable, so it will be well broken up into fine crumbs. Soggy soil studded with clods discourages the growth of any plant or seed. Hoe each furrow about three or four inches deep. Rows in the garden should be 30 to 36 inches apart—wide enough to permit tilling, hilling, or mulching between them. If you plant in a raised bed, the furrows can be closer, about a foot or so apart. Enrich the furrow with an inch or two of compost, well-aged manure, or bagged dehydrated manure. (Do not use fresh manure, as it may encourage disease.) Mix it with the soil in the bottom of the furrow.
Planting
Set the seed-potato pieces in place about 10 or 12 inches apart in the furrow. (In the rich soil of a raised bed, you can plant them slightly closer.) Plant them cut-side down, so the eye will be uppermost, and press them firmly into the soft soil. At this time, place about 1 to 2 tablespoons of 12-12-12 fertilizer between the potato pieces. Then rake about three inches of fine loose soil over them. (After potatoes start growing, fertilize again with 12-12-12.)
Hilling Up
The new crop of potatoes will form above, not below, the seed potatoes you planted. Hilling up the row gives them an easily penetrated mound of soil to grow into and prevents greening from exposure to the sun. (Green potatoes are unfit to eat because they contain the toxic alkaloid solanine.) Hilling is easier done right after rototilling the paths between the rows or beds, when the soil is loose and deeply worked. If you garden with hand tools, use a garden fork to loosen the soil first. Use a hoe or rake to draw up the loose soil from the aisles, banking it high over the potato plants but leaving four or five inches of stem and leaf uncovered.