Published on 01/14/98

Eager Gardeners Look to Potato-planting Time

Many Georgia gardeners aim to have tilled their gardens and planted their "seed" potatoes on or around Valentine's Day. Others will be lucky to have them planted by tax time.

Because our weather can be so unpredictable, it's hard to be precise when advising on planting time. Potatoes are considered a cool-season crop. They can be planted as soon as the ground has thawed and dried enough.

It's critical to let the soil dry enough. If you work it while it's still too wet, soil becomes hard and compacted. That can lead to long-term frustrations for the eager gardener.

The potato plant can adapt to most types of soil. But it must have good drainage to keep the potatoes from rotting before they can be harvested. Choose a sunny place and work in 2 to 3 pounds of a balanced fertilizer, such as 12-12-12, per 100 square feet to promote vigorous plant growth.

The part of the plant we eat is called a tuber, a technical name that refers to an enlarged modified stem that grows underground. Potato tubers used to create a new planting are called seed potatoes.

You'll want to start with the best quality seed potatoes, so look for those labeled "certified disease-free" at garden shops and in mail-order catalogs. Don't try to use store-bought potatoes.

There are two kinds of potatoes: better and best. Just kidding. There are "whites" and "reds." The whites are best used for baking and frying, while the reds are best for boiling and potato salad. Both grow well in our area.

New potatoes out now, such as Yukon Gold and those with purple skin and flesh, can add novelty to your garden.

To start a new planting, cut the seed potato into pieces so each piece has at least one healthy-looking bud (often called an "eye"). That bud will become the shoot of the new plant. As the stem develops, it also will produce new roots.

The piece of tuber attached to the bud provides a source of carbohydrates to sustain the young plant until those new roots and shoots develop.

Plant the pieces 2 to 3 inches deep. Space them about 12 inches apart in the row, and leave 24 to 36 inches between rows.

New tubers that will become this year's harvest generally begin to form sometime in early summer. They continue to grow as long as they have enough moisture, air and nutrients.

The tubers can be dug as "new" potatoes -- before they reach full size and before the skins start to toughen. New potatoes are tender and tasty, but they don't keep very long. Since the plant must be pulled up to harvest the tubers, yields are generally small.

If you want bigger yields of full-size tubers, it's best to leave the plants until they begin to die back on their own. As the plants begin to turn brown, gently lift the tubers with a digging fork and remove them from the plants.

If the potatoes are going to be used right away, no further treatment is needed. However, to be able to store the potatoes for later use, you'll want to let the tubers "cure," or air-dry, for one to two weeks to allow the skins to thicken and dry.

The biggest challenge for gardeners is finding dark storage space with a cool temperature. Both light and warmth promote sprouting of the buds. For best results, store only the best quality tubers that are free of cuts, bruises and diseases.

Wayne McLaurin is a professor emeritus of horticulture with the University of Georgia College of Agricultural and Environmental Sciences.