The potato “eye” is a small bud on the tuber’s surface, representing the growing point from which a new plant emerges. Potatoes are propagated vegetatively, not from true botanical seeds. Planting whole tubers is inefficient, so gardeners cut larger potatoes into smaller portions, known as seed pieces, to maximize planting material. This allows each viable eye to develop into a separate, productive plant, yielding a greater harvest.
Selecting and Preparing the Tuber
A successful potato harvest begins with choosing high-quality, certified seed potatoes that are disease-free. Grocery store potatoes are often treated with sprout inhibitors, making them unreliable for planting. Sourcing certified seed stock ensures the genetic health and vigor necessary for robust growth.
If seed potatoes have not sprouted naturally, “chitting” or pre-sprouting can give the plants a head start. Place the tubers in a warm location (60 to 70 degrees Fahrenheit) with indirect light for two to three weeks before planting. The light encourages short, sturdy, dark-green sprouts rather than the long, pale shoots that form in the dark. Tubers smaller than 1.5 inches in diameter should be planted whole and do not require cutting.
Step-by-Step Guide to Cutting Potato Eyes
Once the tubers are selected and pre-sprouted, use a clean, sharp knife to divide the larger potatoes into individual seed pieces. The size of each piece determines the young plant’s initial energy supply. An ideal seed piece should be block-shaped, approximately two inches square, and weigh between 1.5 to 2.5 ounces.
Each cut piece must contain at least one to two strong, visible eyes to ensure successful sprouting. Cutting the potato into segments allows the gardener to distribute the eyes across multiple plants, effectively multiplying the seed stock. Cut away from the eyes, leaving sufficient tuber flesh. This flesh provides the necessary carbohydrates and moisture to nourish the developing sprouts and roots until they establish themselves in the soil.
Curing Cut Pieces Before Planting
After cutting, the exposed surfaces must be cured, or callused, before planting. This process is a defense mechanism against pathogens. Spread the seed pieces in a single layer in a dark, well-ventilated area for two to five days.
This drying time allows the cut surface to form a thick, protective layer of cork cells, known as a callus. This dense barrier seals the internal tissues, reducing the risk of rot and fungal infections when planted in cool, damp soil. A proper cure is important if planting occurs in cool or wet conditions, which can delay growth and encourage decay.
Planting the Prepared Seed Pieces
Once the seed pieces are properly callused, they are ready to be planted when the soil temperature is reliably above 45 degrees Fahrenheit. Potatoes thrive in loose, well-drained soil cultivated to a depth of six to eight inches. Place the prepared seed pieces cut-side down, ensuring the eyes or sprouts face upward.
Plant each piece four to six inches deep in a trench or hole. Spacing the seed pieces 12 to 15 inches apart allows each plant ample room to develop a full set of tubers. Covering the seed pieces with a few inches of soil initially, then gradually adding more soil as the plant grows, is called hilling, which encourages a larger yield.