Potatoes - Illinois Vegetable Garden Guide - University of Illinois Extension



Potatoes grow best in a long, cool season, which is rarely found in Illinois, but if recommended practices are followed, satisfactory yields can be obtained. The crop must be planted as early as the soil can be worked in the spring.

Always use certified seed potatoes, which are free of disease. Cut these potatoes into blocks weighing about 1½ ounces each. Make sure that each seed piece has at least one eye. Plant immediately.

Close spacing (30 inches between rows and 12 inches between plants) is recommended for early potatoes so that the plants will shade the soil and prevent excessively high soil temperature during the time the tubers develop. Mulching the potatoes with about 8 inches of loose straw when the plants are 6 inches high will also lower the soil temperature as well as control weeds, conserve moisture, and improve the keeping quality of the potatoes.

potato bareground

Many diseases and several insects cause trouble in potatoes. By using certified seed potatoes and resistant varieties, and by spraying or dusting at 10- to 14-day intervals with a recommended fungicide and insecticide, most insects and diseases can be controlled. Do not save your own seed.

Harvest the potatoes after the vines have died. Before storing, hold potatoes for a week or two at 65° to 70° F. in a place where the air is not too dry, to heal cuts and bruises. Then store them where the temperature will be 35° to 40° F. At lower temperatures potatoes will become sweet and at higher temperatures they will sprout. To prevent sprouting, treat potatoes after cuts are healed with one of the sprout inhibitors now on the market.

Crop Amount for 100
ft of row
Variety recommended for use in Illinois Days to harvest Resistant to
Potatoes (seed) 10-12 lb Early
Irish Cobbler 100
Norgold Russet 100
Norland 105 Scab
Superior 105
Red Lasoda 110
Red Pontiac 110
Katahdin 120 Verticillium wilt
Kennebec 120 Late blight
Vegetable Hardiness Recommended planting period for central Illinois (b) Time to grow from seed to field (c)
For  overall
Potato Half-hardy Apr. 1-15
June 1-10
June 1
Vegetable Spacing in row
Seed to sow per foot Distance between plants when thinned or transplanted Distance between rows Planting depth
inches inches inches
Potato 1 10-12 24-36 4