Potatoes have eyes or buds, which become the seed pieces from which new plants grow. From the new plant, many potatoes (or tubers) form on the roots. Each of these tubers is full of eyes. Such is the miracle of potato reproduction.
There are indentations in the potato skin with small nodules within them. These are the potato eyes or buds. When planting potatoes, the buds or eyes are cut into 1- to 1 1/2-inch squares, then placed, with the flat side down, into a trench. The trench is covered with about 4 inches of soil and within about two weeks, the potato seed will sprout and a new plant is born. Sometimes whole small potatoes are planted to create the new plant, instead of just the potato eyes.
Agriculture extension agencies recommend using only "certified" seed potatoes to limit diseases and inconsistencies.
People plant potato eyes because potatoes are an important part of the human diet. They store well and can be cooked in a wide variety of ways.
The common name for potato is white potato or Irish potato. The proper Latin name is Solanum tuberosum L. It is an annual plant. A member of the nightshade family or Solanaceae, the potato is closely related to tomato, pepper and eggplant. The part that people harvest and eat is actually a tuber. The tuber is the enlarged end of a stolon, or an underground stem. Tubers or potatoes contain carbohydrates, which makes them a starchy food. They also contain protein, calcium, niacin and vitamin C.
Even though the potato originated in Peruvian Andes, most potatoes grown today are actually descendants of a Chiliean cultivar.
Sixteenth-century Spanish explorers introduced the potato to Europe, where over the next few centuries, it became a food staple. By the 1800s, potato was the main crop of Ireland.
Between 1845 and 1847, there was a potato blight in Ireland that resulted in widespread famine and poverty. Nearly one million people died, while one million more emigrated to North America. Potatoes became so associated with Ireland, that even today they are commonly called "Irish" potatoes to distinguish them from the unrelated sweet potato.
The potato was brought to North America by immigrants. It was first grown as a large crop in New Hampshire in the early 1700s.
Today, potatoes are the world's fourth-largest crop, behind wheat, rice and corn.
Potatoes are a cool-season crop. Optimal soil temperature for tuber growth is between 60 and 70 degrees F. Potatoes prefer a loose, light, well-drained soil with a pH of about 5.0 to 6.0. They thrive in full sun.
Heavy or clay soils retain too much water, which can cause new potatoes or tubers to rot in the ground. Heavy or clay soils must be amended with compost or other materials to make them drain better.
Some people avoid growing in soil altogether through the use of straw planting. In straw planting, the seed pieces are placed on top of the ground and straw is deposited liberally on top of them. With this method, the potato sprouts will grow upward through the straw, while the tubers grow on top of the soil, beneath the straw. This method eliminates the need for cultivating, weeding and "hilling."
Hilling is the process whereby several inches of dirt is pulled up around plants at various intervals (every two weeks or so). The aim of hilling is to give the plant and tubers more growing area, to keep insects away from tubers and to ensure that tubers are never exposed to sunlight.
Potatoes or tubers should mature in 90 to 30 days after planting, depending upon the cultivar.
It is possible to harvest both a spring and winter crop of potatoes.
The first potatoes harvested in the spring are called "new" potatoes.
Potatoes are "cured" for 10 to 14 days after harvest in controlled temperatures of 15 to 18 degrees C with ideal humidity levels of 90 percent to 95 percent. Afterward, they can be stored for up to 8 months in low temperatures, kept dry and out of sunlight.
Maleic hydrazide is often sprayed on commercial potatoes to keep them from sprouting in warm temperatures. This is one reason store-bought potatoes are not recommended as a seed source.
The purpose of "hilling" a potato plant is to get rid of weeds and to keep the tubers from exposure to sunlight. Sunlight turns tubers green and causes them to produce poisonous glycoalkaloids. To be considered non-poisonous, newly released cultivars must have less than 20mg glycoalkaloids per 100g fresh weight. Do not eat green potatoes.
As a root vegetable, potatoes absorb whatever is in the soil. Steer clear of pesticides and contaminated areas when growing root vegetables.