Growing Potatoes

Potatoes
Posted on January 18, 2012 by Rick Bickling


Overview
The Potato (Solanum tuberosum) is a member of the Nightshade family of plants. The edible part of the potato plant is called a tuber, not a root, and there are many different varieties of red, white, yellow, russet, and even purple or blue potatoes. Potatoes originated in South America, and were grown as a food crop by the Incas as early as 3,000 BC. The Spanish conquistadors brought the potato back to Spain around 1530, and it was introduced to the United States in 1719 when Irish immigrants brought it with them to New Hampshire. French fries were first introduced to the United States when Thomas Jefferson served them in the White House during his presidency in 1804.

Nutrition Facts
Potatoes are nutrient-rich vegetables, full of carbohydrates.
Serving Size: 5 oz. Potato (baked or boiled with skin)
Calories…… 150
Recommended Daily Values:
Vitamin C…. 45%
Potassium…. 21%
Thiamin…… 10%
Niacin……. 8%
Vitamin B6… 14%
Folacin…… 14%
Fiber…….. 3 grams
Fat………. 0 grams
Protein…… 4 grams
They also contain smaller amounts of iron, magnesium, phosphorus, and pantothenic acid.


Soil Preparation
Potatoes grow best in full sun in loose, slightly acidic soil that is well drained. Before planting potatoes, remove all rocks, trash and weeds from the planting area and till the soil to a depth of 8 to 12 inches. To help prevent disease, be sure to practice proper crop rotation by NOT planting potatoes in soil in which potatoes, or any other member of the Nightshade family such as tomatoes, peppers, or eggplant, were grown in the past two years.

Seed Preparation
Unlike most vegetables, potatoes are not grown from seeds but from potatoes that were grown the previous season, seed potatoes. Always use certified disease-free seed potatoes that are free of chemicals. Do not use potatoes from the grocery store for planting.

The “eyes” on the seed potato are actually buds that, when planted, will sprout into new potato plants. Cut large seed potatoes into pieces about the size of an egg, and having at least one good eye. Cut the seed potatoes 5 or 6 days before they are to be planted and let them sit in a cool, well-ventilated area to heal, or cure, in order to help prevent rotting once planted.

Planting
Potatoes are cool-season herbaceous perennials that are grown as an annual. Potatoes can be planted once the soil temperature 5” deep has reached 50 degrees F, or about 3 weeks before the last spring frost. In some areas, a fall crop can be planted about 110 days before the first frost. They grow best when daytime temperatures are around 65 to 70 degrees F.

Photo © Texas AgriLife Extension Service
Plant the seed potato pieces to a depth of 3 inches with the pieces spaced about 10 to 12 inches apart and the eye facing up. Sprouts from the seed potatoes will emerge in 2 to 4 weeks. As the new potato plants grow, regularly pile dirt up around the base of the plants to just below the leaves. This is done because new potatoes only grow in the soil area above the seed potato piece and below the top level of the soil. Be sure to keep the new tubers covered with soil to prevent them from turning green.

Potatoes can be easily grown in raised beds, baskets, barrels, or stacks of old tires where additional soil can be continuously piled up around the plants as they grow. Just be sure that the container is well drained.

Potato plants usually produce flowers and, and sometimes small fruit, that are attractive but should not be eaten.

- See Chart Below for Recommended Varieties -

Fertilizing
Potatoes prefer an acidic soil with a pH between 4.8 and 5.5. Apply a complete 10-20-10 fertilizer to the soil just before planting. After the seed potatoes sprout, fertilize your plants once a week with an application of a balanced fertilizer such as Miracle-Gro Vegetable Food.

Watering
Once planted, water the potatoes regularly to keep the soil evenly moist. Potatoes need at least 1 inch of water per week. Water early in the morning to allow plants to dry quickly and reduce the opportunity for disease infection. Drip irrigation is recommended to allow the water to get right to the growing tubers.

Weed Control
Keep the garden free from weeds, as weeds will compete with the growing potatoes for soil nutrients and water. Do not dig too deep when using a hoe, or pulling weeds to avoid damaging the tubers.

Insects
The lava of the Colorado potato beetle are red, or light orange with two rows of black dots on each side, while the adult has black and yellow stripes. Both are about 3/8 of an inch long and feed on the leaves of the potato plant. The best way to remove them is to hand pick them from the plants.

Aphids are small, whitish insects that may be found in masses on the underside of leaves. If present, leaves become yellow, sticky with honeydew. Hose off underside of leaves to knock off aphids.

Wireworms are thin, about ½ to 1½ inches long, worms with a dark head and tail that feed on the carrot root. Apply a Bacillus thuringiensis (Bt) based insecticide to control them.

Leafhoppers are green wedge shaped insects about 1/8 of an inch long. They will suck the juices from leaves causing them to curl upward and turn yellow or brown. They can be hosed off of the plants with a hard stream of water.

Diseases
Diseases and fungus may be a problem for potatoes during cool, wet weather. Check your plants regularly and when needed, treat with Neem oil, sulfur, or an applicable fungicide.

Harvesting
Potatoes will be ready to harvest in about 95 to 110 days, when the tops of the plant begin to die and each potato weighs from 6 to 12 ounces. You can harvest small “new potatoes” during the growing season by carefully digging beside the plant with your fingers. To harvest mature potatoes, use a spading fork to dig under the plant, 8 to 10 inches out from the stem, then pry the entire plant out of the ground and shake off any loose soil.

Storing
Carefully pull the potatoes from the vine and store them in a cool dry place with plenty of air circulation and a temperature of about 40 to 50 degrees F. Do NOT store them in the refrigerator and Do NOT wash them before storing them. Potatoes may be stored in an underground root cellar, and under the right storage conditions will keep for two to three months.