Photo: Scott Bauer, USDA-ARS
Spanish explorers took potatoes to Europe from the Peruvian Andes. Europeans were slow to accept them, because they belong to the nightshade family, which has many poisonous members.
Once accepted, though, potatoes quickly became a staple crop, particularly in Ireland, where the rich soil and cool climate are perfect for growing them.
In 1845, late blight (Phytophthora infestans) struck, wiping out the crop for two years. During the subsequent famine, 750,000 to 1.5 million people starved to death.
Ireland didn't recover from the famine for the rest of the century, its population falling from more than 8 million to fewer than 5 million. More than 1.5 million Irish people emigrated to the United States, contributing to the large Irish-American population here today.
You Don't Have to Buy Them
Potatoes are an important commodity in America today. U.S. farmers grew more than 47 million pounds in 1998.
Although potatoes are widely available, you can grow them yourself.
First, take a soil test to determine pH and soil fertility. Potatoes grow best in acid soils with a pH of 5.0 to 5.5. A pH above this will increase the occurrence of scab, a disease of potato.
Use elemental sulfur to lower the pH. Lime will raise it.
The soil should be well-tilled and drain easily. Standing water causes potatoes to rot in the ground. If your soil is prone to standing water, use raised beds to improve drainage.
Potatoes Need Ample Nitrogen
Potatoes are fairly heavy feeders. They require about 1 pound of nitrogen per 100 feet of row in south Georgia coastal plain soils. They need slightly less than that in the Piedmont, mountain and Limestone Valley soils of north Georgia.
Set phosphorus and potassium rates based on the soil test. If you don't take a soil test, apply at 1east 1 pound of phosphorus and potassium per 100 feet of row.
Split fertilizer applications for more efficient use. Incorporate one-third before planting, one-third after emergence, and one-third three weeks after that.
Use Certified Seed Pieces
Start with certified seed pieces. Buy them from your local garden center, feed and seed, or by mail order. Often, these seed pieces have been treated with a fungicide, which will help prevent soil-borne diseases.
It takes about 15 pounds of potato seed pieces to plant 100 feet of row. Space rows about 36 inches apart with seed pieces every 8 to 12 inches.
Plant in mid-February in south Georgia, mid-March in central Georgia and by April 10 in north Georgia.
Plant, Bed, Harvest
Seed pieces should be planted 3 to 4 inches deep. As plants emerge and begin to grow, bed up the soil around the plants to encourage more potatoes, since all new potatoes will form above the seed piece.
Potatoes should be ready for harvest three to four months after planting, depending on variety and environmental conditions. They're ready for harvest when the tops turn yellow and begin to die. Take care not to damage the tubers as you dig them.
You can store potatoes three to five months if you keep them cool. But store only potatoes free of damage and disease.
For Best Storage...
Hold them at 60-70 degrees for at least four days before storing them at 40 degrees. An unheated cellar or similar place is ideal for potato storage.
Potatoes in cool storage for a long time may develop high sugar content and taste sweet. These potatoes turn dark when cooked.
To eliminate the sweet taste and dark color, raise the storage temperature to 70 degrees for one to four weeks before cooking.
Potatoes are rich in complex carbohydrates, fiber, vitamin C and magnesium, with no fat or cholesterol. Enjoy.
(George Boyhan is a Cooperative Extension horticulturist with the University of Georgia College of Agricultural and Environmental Sciences)