By Richard Jauron
Iowa State University Extension
One of the most popular vegetables in the home garden is the “Irish” potato. A native of South America, the potato didn't become an important food crop until it was introduced to Ireland in the sixteenth century.
Potatoes prefer loose, fertile, slightly acid soils. Don't apply large amounts of organic matter, such as manure, to the soil where potatoes are to be grown. The addition of organic matter may increase the occurrence of potato scab. If a soil test has not been conducted, an application of 1 to 2 pounds of an all-purpose garden fertilizer, such as 10-10-10, per 100 square feet should be adequate for most home gardens. Broadcast and incorporate the fertilizer shortly before planting.
Since potatoes are susceptible to several serious diseases, buy certified, disease-free potatoes at garden centers and mail-order nurseries. Potatoes that remain from last year's crop may carry undetectable diseases. Potatoes purchased at supermarkets (for table use) have usually been treated to prevent sprouting. Best results (excellent quality and high yields) are obtained with certified seed potatoes.
Gardeners can purchase seed pieces (tubers that have been cut into sections) and whole potatoes. Small potato tubers may be planted whole. Large potatoes should be cut into sections or pieces. Each seed piece should contain one or two “eyes” or buds and weigh approximately 1.5 to 2 ounces. After cutting the tubers into sections, place the freshly cut seed pieces in a humid, 60 to 70 degree F location for one or two days. A short “healing” period allows the cut surfaces to callus or heal over. Callused seed pieces are less likely to rot in cool, wet soils.
Potatoes should be planted in early spring. Appropriate planting times are late March or early April in southern Iowa, early to mid-April in central Iowa, and mid to late April in northern portions of the state. Plant seed pieces (cut side down) and small whole potatoes 3 to 4 inches deep and 1 foot apart within the row. Rows should be spaced 2.5 to 3 feet apart.
Suggested potato varieties for Iowa include:
Red Norland is an early maturing red variety that produces oblong, smooth potatoes with shallow eyes. They are excellent boiled or mashed, but are only fair when baked.
Russet Norkotah is an early season russet variety that produces blocky, oblong potatoes. It is an excellent baking potato.
Yukon Gold is an early season yellow-fleshed variety. They are excellent baked, boiled or mashed. The potatoes also store well.
Superior is an early to mid-season variety with round to oblong tubers and medium deep eyes. The potatoes are very good baked, boiled or mashed. It is resistant to scab.
Goldrush is a mid-season variety that produces oblong to oval tubers with a russet skin and white flesh. Baking quality is very good.
Katahdin is a late maturing white variety that produces smooth, round, shallow-eyed tubers and is excellent for baking.
Kennebec is a late maturing white variety with block-shaped tubers and shallow eyes. Cooking quality is excellent.
Red Pontiac is a late maturing red variety. Potatoes are oblong with deep eyes. It produces high yields with many large tubers. Table quality is only fair. Storage quality is very good.
While the standard potato varieties listed above perform well in Iowa, there are other varieties with unusual colors and shapes. All Red, for example, is a mid-season variety that produces medium-sized tubers with a red skin and pale pink flesh. Russian Banana produces small, banana-shaped tubers, which are excellent in salads. Heirloom and novelty varieties are tasty and fun additions to the vegetable garden.