Growing Potatoes in the Garden
Posted: May 2, 2012
Potatoes need six hours of sun daily and an acidic soil (pH 4.8 to 5.5). Light, loamy soil is best for full potato formation. A soil test is recommended to determine soil nutrient conditions.
Certified seed potatoes (small, whole potatoes that have been certified disease-free) may be purchased at a nursery or online. Seed potatoes the size of an egg or smaller can be planted whole; larger potatoes should be cut into pieces the size of an egg with at least one eye (sprout).
If the soil is loamy and well-drained, the potatoes can be planted that day. To avoid rotting if the soil is too wet for planting, the pieces should be cured, or left at room temperature in a sunny location, for 4 to 7 days before planting.
Plant potatoes once the temperature of the soil reaches 40°F, or about two weeks before the last frost date. A common method of growing potatoes is using the trench/hill method. A 4 to 6-inch trench is dug with a hoe,and the seed pieces are placed cut-side down 12 inches apart. Trenches should be three feet apart. Cover the seed pieces with 4 inches of soil.
Once the plants are 8 inches tall, a hoe can be used to begin hilling the soil around the base of the plants. Hilling prevents the potato tubers from being exposed to the sun, which causes the skin to turn green and become inedible. Hilling can also help prevent certain diseases.
Potatoes need 1 inch of water per week for optimum growth. A mixture of 4 parts cottonseed meal (N) to 2 parts each of bone meal (P), greensand (K), and kelp meal (K), is a good organic fertilizer that provides the necessary macronutrients to the plants. N is nitrogen, P is phosphorus, and K is potassium. It can be added to the trench prior to planting, and as a side dressing once the plants develop flowers.
For full-sized potatoes, wait until the foliage has died back. Cut the foliage at ground level and wait two weeks. This allows the potato skins to thicken, which means longer storage time. Use a pitchfork to turn the soil over about 6 inches from the side of a hill to collect potatoes. Store the potatoes in a dark, cool place.