Plant Common Name
A vegetable of historic proportions, the potato is the world's most important root crop and fourth largest food crop. Though the origin of the modern potato isn't precise, it is believed to have originated from the northern Andes of South America. Archaeological evidence suggests potatoes were eaten as long as 13,000 years ago in Chile, and hundreds of unique ancient cultivars still exist across the Andes today. The first European explorers encountered potatoes in Colombia where the natives cultivated them near their mid-elevation villages. The fleshy, starchy tubers became accepted in Europe shortly after and by 1600 were widely cultivated across the continent. Their vast popularity in Ireland led to the catastrophic impact of the potato blight. Modern potato hybrids are tougher, more vigorous and genetically diverse.
Potatoes are tender perennials that are typically grown as annuals. They are bushy and have crinkled compound green foliage. Some cultivars develop a sprawling, almost vine-like habit. Their small, star-shaped, white, lavender, or pink flowers bloom in summer and often lack fertile male pollen. Bees pollinate the fertile blooms and small, round, seed-filled fruits follow.
Fleshy potato tubers develop from underground stems and may have brown, golden tan or reddish skin and white, yellow, pink or even blue flesh. The small eyes on each tuber are leaf buds that can sprout to form new plants. All green parts of the potato plant are poisonous.
There are hundreds of cultivars. Some are early tuber producers and others late. Early types take 75 to 100 days to mature, medium take 100 to 120 days and late maturing varieties more than 120 days. Early potatoes tend to perform better in smaller spaces.
Grow potatoes in full sun and fertile, rich, loamy soil that’s evenly moist but well-drained. Plant seed potatoes deep along berms to increase productivity and make harvest easier. Drought stress and high heat will reduce productivity significantly and cause foliage to die back. The potato is a cool season crop typically grown when conditions are moderately warm and pleasant. In frost-free, subtropical areas they are grown in winter or spring when conditions are more favorable.
Potato beetles are the chief pest and must be regularly removed or they will completely defoliate a plant in no time. Fungal blights also destroy crops. Regular rotation of potato crops will reduce the instances of re-infection with soil-borne fungal diseases.
Potatoes are rarely propagated by seed. Instead, whole small tubers or chunks of tubers with eyes are planted. These are called "seed potatoes" and produce exact clones of parent plants. In temperate regions potatoes should be planted one to three weeks before the last frost date. Though susceptible to frost, they are slow to emerge from the soil. The new shoots can be protected from late frosts with frost cloth. As plants emerge, the soil can be mounded even higher around them to build the hill. Any exposed tubers should be immediately covered because sunlight causes them to turn green and green potatoes are inedible.
After flowering, the plants start to develop their tubers. Once the foliage begins to turn yellow, the tubers may be dug up and eaten, though it is common to raid potato mounds early for new potatoes. The tubers should be stored in a cool, dry, dark location where they can last for months. Never chill potatoes as this will cause them to become sweet and unpalatable.
There are thousands of potato varieties, some that are best grown in the north and others that are best for the south. So, it is wise to research potato varieties and choose one suited to your region.