Red potatoes, known for their thin skin, waxy texture, and suitability for boiling and roasting, are often harvested early as “new” potatoes. Achieving a healthy and abundant harvest depends significantly on managing the planting density. Proper spacing ensures each plant receives adequate sunlight, water, and nutrients, which is the single most important factor for maximizing both the size and quality of the tubers. Overcrowding can lead to competition for resources, resulting in many small, underdeveloped potatoes and increasing the risk of disease transmission due to poor air circulation.
Preparing the Seed Potatoes
The journey to a successful red potato crop begins with preparing the seed pieces before they enter the soil. Planting small, golf ball-sized seed potatoes whole is acceptable, but larger tubers should be cut to increase the total number of plants. To create a viable seed piece, ensure each blocky section is roughly the size of a chicken egg, weighing between 1.5 and 2.5 ounces.
Each cut piece must contain at least one healthy “eye,” which is the dormant bud from which the new plant will sprout. Many gardeners aim for two to three eyes per piece to ensure vigorous growth. Once the seed potatoes are cut, they should be left to cure in a dry, well-ventilated location away from direct sun for one to three days.
This curing process allows the cut surfaces to dry and form a protective, cork-like layer, or callous. This protective layer prevents the seed piece from rotting once planted, particularly in cool, moist soil conditions. Planting uncured seed pieces exposes the soft inner tissue to soil-borne pathogens, leading to decay before the sprout can even emerge.
Optimal Spacing for High Yields
The precise distance between your red potato plants determines whether you harvest small, tender “new” potatoes or larger, mature tubers. For growing red potatoes, which are typically desired for their smaller size and early harvest, a slightly tighter in-row spacing is often employed. Placing seed pieces about 10 to 12 inches apart within the trench generally encourages the production of more numerous, smaller-to-medium potatoes per plant.
If the goal is to produce fewer, larger-sized red potatoes for storage or baking, increase the spacing to 14 or 15 inches between plants. This wider distance reduces competition, allowing the individual plants to develop a more extensive root system and dedicate more energy to fewer, bigger tubers.
The row-to-row spacing should be a minimum of 24 to 36 inches apart. This distance is necessary for proper air circulation around the developing foliage, which helps prevent fungal diseases such as late blight. Wide rows also provide sufficient space to perform the technique of hilling without damaging the plants.
Planting Depth and Hilling Requirements
The seed potato piece should be planted in a trench or hole at an initial depth of approximately four to six inches. This initial depth provides a stable base for the plant and protects the emerging sprouts from late frosts. As the plant begins to grow, hilling becomes necessary to ensure the developing tubers remain underground.
Hilling involves mounding loose soil, compost, or straw around the base of the plant stem. Potatoes form along underground stems called stolons, and these stolons only develop tubers in the dark, buried environment. The first hilling should occur when the plant is about six to eight inches tall, covering the lower half of the plant and leaving only the top leaves exposed.
This process must be repeated as the plant continues to grow, usually when the foliage has reached another six inches in height. Hilling prevents sunlight from reaching the developing tubers, which would cause them to turn green and produce the mildly toxic compound solanine. By building a tall, loose mound, you maximize the vertical space available for new tuber formation, which directly increases the overall harvest yield.