By Judy Kunz, Colorado Master Gardener
Originating high in the Andes Mountains of South America around 5000 to 8000 BCE, the potato has emerged as one of the most important crops worldwide, along with wheat, corn, rice and sugar cane.
Spanish conquistadors brought potatoes from South America to Europe around 1532. From Europe, potatoes spread throughout the world and made their way to North America by the early 1600s. Because of its high productivity, nutritional value and relative resistance to disease, the potato fed millions of Europeans. Its arrival and subsequent mass cultivation ended famine and fueled the rise of the West between 1750 and 1950.
However, late blight (phytophthora infestans), a fungus thought to have originated in bird guano (excrement) which was used as nitrogen-rich fertilizer, eventually ended in disaster for potato farmers throughout Europe. Thirteen million tons of the popular and inexpensive guano were transported by ship from islands located off the coast of Peru. The arrival of late blight devastated potato crops as it hopscotched around Europe and caused widespread famine, the most disastrous being the Irish Potato Famine of 1845. One million Irish died of starvation and two million fled the country. As a direct result of the devastating famine, one and one-half million Irish citizens subsequently emigrated to the U.S.
In addition to p. infestans, a major pest of potatoes worldwide has been the Colorado potato beetle (leptinotarsa decemlineata). Despite its name, the potato beetle had its origins in central Mexico. The insect feeds on the above ground foliage of the potato plant thereby inhibiting the growth of the tubers. Powdery scab (Spongospora subterranean), a fungus-like pathogen has become a concern for potato growers in recent years. First identified in 1913, it also can be a devastating disease, causing major lesions on the potato and galls on the roots.
More recently, ongoing genetic research into potato diseases has resulted in disease resistant varieties, making it a major staple in many societies around the world. The International Potato Center in Peru has identified over 5,000 known varieties, many of them disease resistant.
In Colorado, total potato production ranks the state among the top ten. Because of its higher altitude, cooler weather, water availability and nutrient-laden soil, the San Luis Valley in south-central Colorado has become an ideal location for growing potatoes. In fact, they are the major cash crop for the area.
Growing Potatoes in the Home Garden
Potatoes are an excellent source of vitamin C, potassium, vitamin B6 and fiber. They are relatively easy to grow but do require some monitoring for consistent soil moisture, insects and disease. They prefer sandy loam soil rather than heavy clay, so it is prudent to have a soil test prior to planting. Adjusting organic content and/or fertilizer according to the results of a soil test will aid in producing a healthy crop.
Potatoes are grown from small chunks of seed potatoes containing one or more “eyes” rather than from seed. Purchase seed potatoes from local garden centers or order them through the mail. Do not use grocery store potatoes. They have been sprayed with growth retardant for longer shelf life. More detailed information about growing potatoes in the home garden as well as several recommended disease resistant varieties developed by Colorado State University researchers are detailed on this CSU fact sheet. Read more about the journey of the potato here.