Garden Fresh Potatoes

North American gardeners grow potatoes that generally fall into 1 of 6 color categories.

University of Minnesota potato growing fact website has a lot of useful information on growing potatoes.

Blue skin with white or blue flesh
Brown skin with white or yellow flesh like
Purple skin with white, yellow or purple flesh
Red skin with white, yellow or red flesh
White skin with white or yellow flesh
Yellow skin with white or yellow flesh

Start your potato plants from tubers or pieces of tubers. Buy disease free seed tubers from a certified grower or seed distributor. Most garden centers carry seed potatoes in the spring.

Potatoes saved from your own garden may not be a good choice either. They can carry disease spores from the previous year. Although your garden may seem disease free, re-introducing more fungi or bacteria could cause crop failure for your potatoes, tomatoes, peppers and eggplant in the future.

Hint: Do not plant potatoes purchased at the grocery store, they may have been treat with chemicals to keep tubers dormant(prevents sprouting), in which case they will be slow to grow.
Diseases may also infect the potatoes, which can remain in your garden soil for many years. Also they may have been treated with pesticides to kill insects that can damage potatoes that have been placed in storage.

Plant your seed potato sections about 3 inches deep. The depth allows the potatoes to form without breaking the surface and causing green spots on the potatoes. When a tuber is exposed to light for an extended period of time, a poisonous alkaloid is produced that turns the potato green.

Before planting, add a fertilizer with a NPK rating 10-10-5. Mix the fertilizer in with the soil as you till to evenly disperse the fertilizer. If you use an organic fertilizer, such as cow or horse manure, make sure the manure is well-rotted or at least a year old. Fresh manure causes the planting bed to get too “hot” and burns the plants.
Potato seeds prefer a cooler temperature to set roots. The ideal soil temperature for planting seed potatoes is around 55 degrees Fahrenheit.

Hill soil up around plants as they grow. Tubers will form on thin stems, called stolons, which emerge from the main stems. The deeper in the soil the underground portion of the plant, the more stolons the plant may grow.

Potatoes are both water loving and heavy feeders of fertilizer. Moisture stress can cause knobby or hollow potatoes, and can prevent the plant from producing new tubers. Light soil is the best for growing large, smooth potatoes. Soak the soil thoroughly when watering, once or twice a week.

You can dig new potatoes about seven to eight weeks after planting. New potatoes will have formed above the seed piece you planted, so dig down about a foot, and turn the whole plant upside down to pick the tubers.
Harvest mature tubers after the plants have dried(look dead) or when tubers have reached full size.