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Growing potatoes is fun and not that hard! Home gardeners can grow unique varieties that are not sold in local supermarkets. Choice of a potato variety for growing in a home garden depends on factors such as garden space availability, desired uses, and storage plans.

To ensure quality and maximum productivity, purchase certified seed tubers. Certified potato tuber seed is seed of a known variety produced under strict standards to maintain seed tubers that are virus and disease free. Saving tubers from your garden will eventually result in decreased yields and small tubers due to more incidences of disease. For the same reason, you do not want to plant tubers from the grocery store. Grocery store potatoes have been treated to prevent sprouting so it may be difficult to even get a plant started at planting time.

Seed Preparation

Depending on the source and the quantity you buy you will receive either small tubers or large tubers. Small tubers (1 to 2 inches in diameter) can be planted whole. Cut large tubers into block‐shaped, 2 to 2 1/2-ounce seed pieces (about the size of an egg). The seed pieces should be firm, with at least one “eye” per section and a maximum sprout length of 1/4 to 1/2 inch to ensure optimum germination. Seed tubers can be cut and planted on the same day, however allowing the cut surface to heal over for 4‐7 days may reduce the risk of seed pieces rotting in the soil.

Soil Preparation

Potatoes grow on a wide range of soils but are best suited to a sandy loam or a soil that is well drained. Fine‐textured soils that are high in silts and clay may not be well drained, and they tend to produce poorly shaped potatoes. The best soil pH for potatoes is between 5.5 and 6.0. Rototill into the seedbed about 2 pounds per 50 feet of row Dairy Doo Heathy Garden fertilizer. Redress with Heathy Garden one week after plant emergence and again between 4-6 weeks after emergence. Instead of working the fertilizer into the soil, water thoroughly so that the fertilizer moves into the root zone.

Do not amend the soil with lime or manure in the same year that potatoes are to be grown. Lime and manure increase the risk of potato scab disease.

Planting and Care

Potatoes are a cool season crop; ideal temperatures for crop growth are 65 to 80 during the day and 55 to 65 at night. The soil should be cultivated 6 to 8 inches deep in the spring, and large soil clods should be broken up or removed before planting. Plant potatoes when soil temperatures are above 45 F. Cold, wet soil at planting time increases the risk of seed piece decay, and planting into cool, dry soils can cause delayed sprouting and emergence of the potatoes. The best time to plant is mid-April to the first week of May.

Plant tuber seed pieces 3 to 4 inches deep. Leaving 30 to 36 inches between rows and spacing seed pieces 9 to 12 inches apart in the row will generally produce an acceptable yield of medium‐sized tubers. You can expect to harvest 3 to 5 pounds of potatoes per potato plant.

Potato plants should be “hilled” when the plants are 8 to 12 inches tall. Mound the soil to a height of 3 to 6 inches and approximately 12 to 15 inches from the base of the plant. Hilling maintains suitable soil cover for tubers as they expand. Tubers that break the soil surface may have green areas that contain bitter tasting glycoalkaloidsand should not be eaten. Discard or cut off the green portions.

Avoid planting potatoes in the same location year after year. To lower the risk of disease and insect problems, do not plant in areas where tomatoes, peppers, eggplants, radishes or beets were grown the previous year.

Water Requirements

Potatoes are very sensitive to soil moisture and do best with a consistent soil moisture level. Even soil moisture levels throughout the root zone should be maintained, though over‐wet and saturated conditions should be avoided. In general, 1 inch of water per week from rainfall or irrigation is adequate. As much as 2 inches per week may be required on sandy soils with low organic matter.

Dry soil alternating with periods of saturated soil can result in poor quality tubers with defects such as knobs, growth cracks, hollow heart and internal browning. Long periods of excess moisture, particularly near maturity, may lead to decreased yields and poor-quality tubers.

Pest and Disease Control

You can help alleviate pest problems by changing the location in your home garden where potatoes are planted, through regular inspection, and by removing “volunteer” potato plants, which can serve as a host for diseases that can damage the new crop.

Shallow cultivation is preferred for weed control. For late season weed control, pull weeds instead of hoeing them to prevent tuber damage. Mulches can be beneficial in weed control as well as helping to maintain soil moisture.

Harvesting

Time of maturity varies for each variety. Indicators of tuber maturity include complete vine death, “skin set” (tuber skin does not peel from the flesh when pressure is applied) and desired tuber size. Mature tubers store better and are less likely to bruise or decay than immature tubers.

New or small tubers can be harvested early without destroying the entire plant by careful digging and removing some of the tubers. The remaining tubers should be left to grow and reach full maturity.

Harvest potatoes before a severe frost. Use a spade or fork to loosen the soil and gently lift the tubers out of the soil. To prevent greening and sunburn damage, do not allow tubers to be exposed to light after harvesting.

Storage

For two to three weeks after harvest, store tubers in the dark at 55 to 60°F with high relative humidity to heal bruised and damaged areas that could provide entrance for disease organisms. Store only the healthy potatoes that are reasonably free from soil.

After healing, proper storage conditions should include cool temperatures (near 40°F), darkness to prevent greening, high humidity and adequate ventilation. Storing tubers in plastic bags (or any tightly sealed container) will restrict the movement of fresh air around the tubers and can lead to rot. A root cellar or garage that does not freeze are ideal storage choices.

By Kelly A. Zarka, Donna C. Kells, David S. Douches & C. Robin Buell, Michigan State University and edited by Kay Landrum