ISU Extension Yard and Garden: Planting potatoes

The potato, one off the most important vegetable crops in the world, is available in cultivars of many shapes, sizes and colors. There are over 1,000 different varieties of potatoes that can be grown in home gardens, including many heirloom potatoes. The texture and flavor are very different from variety to variety. Iowa State University Extension and Outreach horticulturists offer guidance on selecting varieties for Iowa and proper planting. To have additional questions answered, contact Hortline at 515-294-3108 or hortline@iastate.edu.

What would be a good planting site for potatoes?  
Potatoes grow best in well-drained, fertile, slightly acidic soils. The planting site should also receive at least six hours of direct sun each day. Do not amend the soil with large amounts of organic matter. The addition of organic matter may increase the occurrence of potato scab.

What are some good potato varieties for Iowa?   
Listed below are several commonly available potato cultivars that perform well in Iowa.  
• Red Norland is an early maturing red cultivar 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 cultivar that produces blocky, oblong potatoes. It is an excellent baking potato.  
• Yukon Gold is an early season yellow-fleshed cultivar. They are excellent baked or boiled. Excellent storage potato.  
• Superior is an early season cultivar with round to oval tubers with buff skin and white flesh. The potatoes are very good boiled. It is resistant to potato scab.  
• Gold Rush is a mid-season cultivar that produces oblong to oval tubers with a russet skin and white flesh. Baking quality is very good.  
• Katahdin is a late maturing cultivar that produces round, shallow-eyed, buff colored tubers. Excellent for baking and boiling. Excellent storage potato.  
• Kennebec is a late maturing white cultivar with oval tubers and shallow eyes. Good for baking and boiling. Excellent storage potato.  
• Red Pontiac is a late maturing red cultivar. Potatoes are oblong with deep eyes. It produces high yields with many large tubers. Table quality is only fair. Very good storage.  

When planting potatoes, do I need to purchase certified seed potatoes?  
It’s best to purchase certified, disease-free potatoes at garden centers and mail-order nurseries. Potatoes are susceptible to several serious diseases. Potatoes that remain from last year’s crop may carry undetectable diseases. Potatoes purchased at supermarkets (for table use) may have 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.  

When should I plant potatoes in the garden?  
Plant potatoes in early spring (early to mid-April in the southern half of Iowa, mid- to late April in the northern half of the state).
Small 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 one-and-a-half to two ounces. After cutting the tubers into sections, place the freshly cut seed pieces in a humid, 60-70°F location for two or three 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.  
Plant seed pieces (cut side down) and small whole potatoes three to four inches deep and one foot apart within the row. Rows should be spaced two-and-a-half to three feet apart.