by Mary Miller | The Gardens on Spring Creek
Potatoes are the bookend crops of the garden. Planted in spring, their harvest is the hallmark of late summer into autumn. Originating on the slopes of the Andes Mountains in South America and cultivated for generations, potatoes were a staple food of the Andean peoples. Hundreds of varieties were grown and were wildly diverse in color, shape, and flavor.
Legend has it that a Spanish ship bound for Europe wrecked at sea, and its cargo of potatoes rode the currents to the coast of Ireland. The Irish people collected the tubers and thus began their long history with the potato. A common gardening adage is to plant your potatoes by St. Patrick’s Day. However, most often, our local soils remain too cold for planting in March. Potatoes require a minimum consistent soil temperature of 45°F to sprout, with optimal growth occurring between 60-65°F—conditions that typically don’t arrive until April. Potatoes require full sun and fertile, loose, well-drained soil to produce the best yield.
It is wise to purchase certified seed potatoes as they are guaranteed to be free of disease that could spread into the soil and adversely affect subsequent growing seasons. One to three days prior to planting, cut your seed potatoes into pieces. Cut pieces should be no smaller than golf balls and must have at least 1-2 “eyes” or buds. Once sectioned, the potatoes will form a dry callous over the cut surface, making them less vulnerable to rotting when planted.
Plant your potatoes in rows 30 to 36 inches apart in deeply tilled soil. Form a trench 8 to 10 inches deep and place the seed pieces 12 inches apart, cut side down with the eyes facing upward. Cover them with 4 inches of soil. As the plants emerge and grow, continue adding soil around the base—a process called hilling. Hilling protects developing potatoes from direct sun exposure, which can cause them to turn green and bitter. It also helps boost yield potential.
Potatoes need to be well watered throughout the summer. This is especially important when the plants are flowering. During this period, the tubers form and regular irrigation is essential for a good crop. When the bushy plants begin to yellow and die back, reduce the irrigation. Once most plants have died back, cut the stems leaving several inches above the soil. Discontinue watering to help initiate curing the potatoes prior to harvest. Curing is a process that toughens and dries the skins for successful storage of the potatoes.
Baby, or “new,” potatoes may be harvested two to three weeks after the plants stop flowering. The main crop is ready two to three weeks after the foliage has died back. Carefully dig until you have found every special spud! Handle them gently to prevent bruising.
Keep harvested potatoes dry and unwashed for two to seven days, out of the hot sun, to complete the curing process. Store them at 40°F.
Growing potatoes connects us to generations of people who have cultivated them and to the friends, family, and farmers growing them today. Enjoy growing white, yellow, red, and purple potatoes this season!