March is a great time to plant Irish potatoes in North Georgia. There are literally hundreds of cultivars of potatoes that come in every shape, color, and size imaginable. Potatoes can be white, red, purple, blue, and yellow. The Irish potato gets its name from the history of the Irish potato famine. The popular term “Irish” potato refers to potatoes that grow during the cool season, unlike sweet potatoes that grow only during the warm season. However, potatoes are not originally from Ireland or native to anywhere in Europe for that matter.
Potatoes are a crop that originated in South America and have been domesticated and cultivated by that native Incan Indians for thousands of years. When European explorers arrived in the New World, they were introduced to potatoes by the Native Americans. Europeans then introduced potatoes to Spain around 1570 and to Ireland by 1760. The popularity of growing potatoes allowed the Irish population to grow rapidly as potatoes became a major food staple.
Unfortunately, because there was little genetic diversity in the potatoes that were introduced to Europe, the potatoes were quickly devasted by a soilborne fungal disease known as Late Blight. This caused a famine throughout Ireland, causing over a million deaths and a mass exodus from the country. Over a million Irish people emigrated to other countries after 1845, which is why many Americans have Irish ancestors in their heritage.
Irish potatoes require cool soil temperatures to grow large tubers and high yields. This is because they are adapted to the higher elevations of Peru, Columbia, and Chile in their native range. The Incas built entire cities such as Machu Pichu on top of the Andes mountains and farmed potatoes in terraced gardens on mountain sides. The ideal soil temperature for growing potatoes is between 60F and 70F degrees at a 4” inch depth.
In North Georgia, that ideal soil temperature only occurs in early spring and late fall. Tuber formation stops when soil temperatures are over 80F degrees, which is a challenge to growing potatoes in our area. If potatoes aren’t fully mature by mid-June, you will just have to harvest small potatoes. Our soil temperatures are generally too warm in the fall to plant potatoes with success. The window for planting in the spring is around early to mid-March when soil temperatures begin to rise above 50F to 55F degrees. If you plant potatoes too early, they will just sit in cold soil and likely rot.
Because the window for growing potatoes in Northwest Georgia is only about three months with ideal soil temperatures, it is recommended that you select a cultivar that matures in about 90 days or less. Some examples of these include Yukon Gold, Red Norland, Pontiac, Irish Cobbler, and Kennebec. If you grow a cultivar that takes longer to mature, then just plan to harvest these “new” potatoes a little early as soil temperatures begin to rise above 80F degrees. Our local UGA weather station is a free tool for tracking soil temperatures online at georgiaweather.net.
Potatoes prefer acidic soils with a pH between 4.8 and 5.4. This is much more acidic that most other vegetables grown in Georgia. Therefore, it is recommended that potatoes be grown in a separate garden spot from other vegetables, so that this lower pH can be properly maintained. A soil test can be submitted to the County Extension office to check soil fertility and the pH of your soil prior to planting. For more information, check out our free UGA Extension publication “Home Garden Potatoes”, Circular 101 on our website.
Paul Pugliese is the Extension Coordinator and Agricultural & Natural Resources Agent for Bartow County Cooperative Extension, a partnership of The University of Georgia, The U.S. Department of Agriculture, and Bartow County. For more information and free farm, lawn, or garden publications, call (770) 387-5142 or visit our local website at extension.uga.edu/bartow.