Potatoes are a cool season vegetable that are among the world’s food staples, ranking number four in the list behind rice, wheat and corn. This native to the South American Andes was domesticated around 7,000 years ago. Sixteenth-century Spanish explorers observed indigenous use of the potato during their travels and brought the first specimens to Europe in the late 1500’s.
Following Spanish introduction, the potato quickly spread to Italy, England, Belgium and the Netherlands. However, distribution into Germany and Western Europe was slowed by early folklore associating the potato with everything from flatulence to leprosy. Historians have speculated that the unattractive appearance of these root crops may have led to this persistent negative connotation and effectively stymied potato cultivation in Germany and Russian for many years.
All European potato varies in the first 250 years of cultivation were derived from the original Spanish introduction, leading to a relatively narrow gene pool and vulnerability to devastating viruses and fungal blights by the mid-nineteenth century. In an ill-fated attempt to widen disease resistance, new potato varieties from Chile were introduced into Europe and North American in the 1800’s, which may have inadvertently introduced, or heightened vulnerability to, the fungus Phytophthora infestans, the microbe responsible for the infamous Irish Potato Famine.
Thankfully, modern horticulture has increased disease resistance among potato varieties and stabilized production since the days of the Irish Potato Famine, making the potato a worldwide superstar of French fries, soups and salads. Many popular varieties of potatoes grow well in our area and are easy to plant and harvest, but need to be started early since they thrive in the cooler part of our growing season.
The potatoes we harvest are not actually roots, as many might think, but are specialized underground storage stems called tubers. Optimal tuber growth occurs at soil temperatures between 60⁰ and 70⁰F, with growth ceasing at about 80⁰F. Therefore, it is important to plant potatoes early to take advantage of favorable soil conditions that will occur in the early growing season.
I always remember hearing that you should plant potatoes around St. Patrick’s Day. Perhaps this recommendation stems from the potato’s notorious history with the Irish, but it does hold true to some extent. In central Illinois, potatoes need to be planted in late March or early April to allow enough time for plants to fully develop before the weather (and soil) warms and growth tapers off. Planting too early can invite rot if soils stay too cool and wet, whereas planting too late may not allow enough time for tubers to fully develop before harvest.
Potato planting methods vary widely from straw bale planting and special containers that enable easy harvesting, to simply planting in raised beds or small mounds of soil. The idea is that the potatoes need good drainage and ample loosed, fertile soil to freely develop tubers. I have always had great success planting my potatoes in a slightly raised, 8-10 inch tall furrow of soil. This can be accomplished with a specialized “hiller” or “furrower” that attaches to your tiller, or by simply hand shoveling the soil into furrows after tillage. Space rows about 24 inches apart with individual potato seeds spaced about 12 inches apart. Potatoes are planted from “seed pieces” which are not seeds as we commonly think of, but rather about 2 oz pieces of cut up potato tuber. Seed potatoes can typically be purchased at retail garden centers this time of year or may be ordered online from a variety of sources. It is important to purchase certified seed potatoes as they have been inspected and certified to be pathogen free.
Along with the great taste of garden fresh tomatoes, fresh potatoes are unrivaled by anything you can purchase at the grocery store. I encourage you to cultivate your own potato crop this summer, or at least visit your local farmers market. Nothing beats freshly harvested potatoes!