Red potatoes, often favored for their fast-maturing nature and thin skins, are a rewarding crop for the home gardener. Achieving a successful harvest relies heavily on proper preparation and planting techniques. Getting the planting depth right directly influences how many tubers the plant can produce. This guide provides the practical instructions necessary to grow a healthy crop, starting with pre-planting steps and moving through the full growing season.
Preparing Seed Potatoes and Soil for Planting
Before planting, secure certified seed potatoes, as these are guaranteed to be disease-free, unlike common grocery store potatoes. Larger seed potatoes should be cut into egg-sized pieces, ensuring each piece contains at least two “eyes,” which are the growth points. Allow the cut pieces to dry for a day or two until a protective layer, called a callus, forms over the cut surface, preventing rot after planting.
“Chitting,” or pre-sprouting, is a preparatory step where seed pieces are placed in a cool, bright, and frost-free location for several weeks. This encourages the development of short, sturdy, deep green sprouts, giving the plant a head start. The soil should be loose, well-drained, and slightly acidic (pH 5.8 to 6.5). Planting should occur in early spring, approximately two to four weeks before the last expected hard frost, once the soil has begun to warm.
Initial Planting Depth and Spacing Requirements
Dig a trench approximately four to six inches deep. This depth provides insulation against late frosts and shields newly forming tubers from sunlight, which is necessary because exposure can cause them to turn green and develop solanine.
Within the trench, place the prepared seed potato pieces with the sprouts facing upward. Proper spacing is needed to ensure air circulation and provide enough room for the eventual hilling process. Space seed pieces ten to twelve inches apart down the row. Rows should be spaced two to three feet apart, allowing sufficient space for ongoing maintenance and tuber development.
Essential Maintenance: The Process of Hilling
Hilling is the most important maintenance practice for potato cultivation, directly influencing the final yield. This process involves mounding soil or organic material around the base of the growing plant stems. Hilling is necessary because new tubers form along the buried stem, meaning covering more of the stem encourages more potatoes to grow.
The first hilling should take place when the potato plants reach a height of about six to eight inches. Gently pull the surrounding soil up around the stem until only the top few leaves are visible. This action prevents developing potatoes near the soil surface from being exposed to light, which would cause them to green and become inedible.
Repeat this mounding process every two to three weeks, or any time the plant has grown another six to eight inches, until the plant begins to flower. Materials like loose soil, straw, or compost can be used for hilling. By the end of the hilling cycle, the initial planting depth will have been significantly increased, maximizing the area for tuber formation.
Watering, Pests, and Knowing When to Harvest
Consistent moisture is necessary for healthy potato development, especially once the plants begin to flower and the tubers start to form. Potatoes require about one to two inches of water per week, and the soil should be kept uniformly moist but never waterlogged to prevent rot and misshapen tubers. Irregular watering can cause growth abnormalities like cracking or knobs on the potato skin.
Gardeners must monitor for common pests like the Colorado potato beetle, whose larvae are particularly destructive to the foliage. Management involves daily inspection and physical removal of the beetles and their orange egg masses from the undersides of the leaves. Disease prevention is aided by avoiding overhead watering, which can contribute to the spread of fungal issues like blight.
Harvesting occurs when the plant’s foliage naturally begins to yellow and die back. For storage potatoes, stop watering and allow the foliage to completely die down, then leave the potatoes in the ground for an additional two weeks. This period allows the skins to “set” or toughen up for long-term storage. After digging, cure them in a dark, humid area at 55 to 60 degrees Fahrenheit for two to three weeks to heal minor injuries before moving them to a final, cool storage location.