Potato, Irish - Care
The soil should be fertile and well drained. Clay soils should be improved with organic matter and plowed deeply in the fall. If space allows, a cover crop such as clover, buckwheat or winter rye grown in the potato bed the year before potatoes are planted improves soil structure, organic-matter content and subsequent potato production.
Mulch is usually beneficial in growing potatoes. After the potato plants have emerged, organic mulch can be applied to conserve moisture, help keep down weeds and cool the soil. Some gardeners cover rows of early potatoes with clear plastic film at planting to warm the soil and promote early growth when the soil temperature is low. When the plants emerge, remove the film to allow the plants to grow unrestricted.
After the potatoes break the surface of the ground, gradually build up a low ridge of loose soil by cultivation and hoeing toward the plants. This ridge, which may become 4 to 6 inches high by summer, reduces the number of "sunburned" (greened) tubers. The object of potato cultivation is to eliminate competition from weeds, to loosen and aerate the soil and to ridge the row. Misshapen potatoes develop in hard, compact soil. Use extreme caution when hoeing near potato plants because developing tubers are easily cut and ruined.
Irrigate to assure uniform moisture while the tubers are developing. A uniform moisture supply also helps to cool the ground and eliminate knobs caused by secondary growth.
Harvest potatoes after the vines have died. Handle as gently as possible during harvest. Because the tubers develop 4 to 6 inches beneath the soil surface, a shovel or spading fork is a useful tool for digging potatoes.
Potatoes for use in early summer ("new potatoes")may be dug before the vines die (usually in July). When the potatoes reach 1 to 2 inches in size, you may wish to dig a few hills to use for soup or to cook with creamed peas or to butter and roast.
Late potatoes are usually dug in August or early September. They keep in the garage or basement for several weeks in their natural dormancy. Store over the winter in a dark room at a temperature between 38° and 40°F with high humidity. Check periodically for spoilage. Temperatures below 38°F cause internal damage to the tubers.
Flea beetles are shiny, usually black, beetles that often are not seen due to their small size (1/16 inch) and ability to jump quickly from plants when disturbed. They attach cabbage, Chinese cabbage, eggplant, radish, spinach, sweet corn, turnip and potato. Flea beetles scratch holes or leave white streaks in green foliage in late spring. Intense feeding results in wilting and dying of leaves and decreased yield.
Leafhoppers are up to 3/8 inch long, green in color, and wedge-shaped. They may migrate from one area of garden to another and hop away in large numbers when foliage is disturbed. They attack bean, carrot, cucumber, Irish potato, and muskmelon. Symptoms of leafhopper damage includes curled or crinkled foliage and "hopper burn" (caused by leafhoppers' feeding, indicated by brown edges on leaves).