Potatoes are one of the most rewarding and popular crops for home gardeners, offering a generous yield from a small initial investment. While the term “slips” correctly refers to the sprouts used to grow sweet potatoes, standard potatoes are grown from “seed potatoes,” which are tubers or pieces of tubers used for propagation. This process involves preparing the seed pieces and planting them correctly to maximize the development of new potatoes underground.
Preparing the Seed Potatoes
Before planting, many gardeners choose to “chit” their seed potatoes, which is the process of pre-sprouting the eyes to give the plant a head start. Place the potatoes in a cool, bright, but frost-free location for four to six weeks before the anticipated planting date. Position the seed potato with the “rose end”—the end containing the most eyes—facing upward. The goal is to develop short, sturdy, dark-colored sprouts rather than long, pale, weak ones, which indicate insufficient light.
Larger seed potatoes should be cut into pieces roughly two inches square, ensuring each piece contains at least one or two healthy eyes. Small tubers, typically around one to one-and-a-quarter inches in diameter, can be planted whole. Using a clean knife and cutting surface helps prevent the spread of disease.
After cutting, the seed pieces must be allowed to “cure” or dry out for one to two days at room temperature. This curing process forms a tough, protective layer, or callus, over the cut surface. This barrier helps prevent the piece from rotting once it is placed in the cool, moist soil.
Optimizing the Planting Location
Selecting the right location and timing is important. Potatoes are a cool-season crop, meaning planting should occur in the early spring, typically two to three weeks before the average last frost date. The soil temperature should have reached at least 45°F, as cold, waterlogged soil can cause the seed pieces to rot instead of sprout.
The planting site requires full sun, meaning the area should receive a minimum of six hours of direct sunlight each day. The soil should be loose, well-draining, and rich in organic matter to allow for easy expansion of the developing tubers. Loamy or sandy loam soils are ideal because they retain moisture while allowing for good aeration.
Potatoes generally thrive in a slightly acidic soil, ideally with a pH range between 5.5 and 7.0. Amending the soil with aged compost is beneficial. Adding fresh manure or lime should be avoided in the planting year, as these can increase the risk of common scab disease. Potatoes are often grown in long trenches in the ground, but they also perform well in large containers, grow bags, or raised beds, provided these setups offer adequate depth and drainage.
Step-by-Step Planting and Initial Care
The physical act of planting begins by digging a trench or hole approximately four to six inches deep. Position the cured seed pieces with the cut side facing down and the sprouts or eyes facing upward. Planting the cut side down helps encourage the downward growth of roots while the sprouts grow toward the surface.
Spacing the seed pieces correctly ensures adequate room for tuber development; typically, they should be placed about 10 to 15 inches apart within the row. If planting in multiple rows, a distance of two to three feet between rows is recommended to allow for sunlight and proper maintenance. The seed pieces are then covered lightly with only two to four inches of loose soil or compost.
After planting, the area should be watered thoroughly to settle the soil and initiate growth. The first instance of “hilling” is performed once the potato plants emerge and reach a height of about six to eight inches. Hilling involves drawing soil up around the stems, covering all but the top few inches of foliage. This action encourages the plant to produce more underground stems, called stolons, where the new potatoes will form. Hilling also shields the developing tubers from sunlight, preventing them from turning green and becoming inedible due to solanine formation.