Yukon Gold potatoes are a highly popular variety in North America, cherished for their rich, buttery flavor and versatile, mildly waxy texture. Developed in Canada at the University of Guelph, this hybrid was released in 1980. Knowing the precise moment to lift these tubers from the soil is the single most important factor for maximizing both flavor and storage life. Successful harvesting requires understanding the plant’s life cycle and employing specific techniques both before and after digging.
Determining Maturity: Timing the Harvest
The harvest window for Yukon Golds involves two distinct periods: gathering small, delicate new potatoes or harvesting fully matured tubers for long-term storage. The earliest opportunity, the “new potato” harvest, arrives quickly, often around 70 days after planting. At this stage, the plant foliage is still green and may be flowering, indicating the underground tubers are small, usually one to two inches in diameter. This early harvest is guided by time rather than by the plant’s visible decline.
New potatoes possess a thin, delicate skin that rubs off easily, meaning they must be handled gently and consumed quickly, ideally within about ten days. They are not suited for extended storage. Harvesting new potatoes is a trade-off, as removing the small tubers prevents them from growing larger, slightly reducing the overall potential yield. Gardeners who prioritize flavor and freshness often perform this early harvest.
The timing for a full-sized harvest, intended for storage, typically occurs between 90 and 110 days after planting. The reliable visual cue for readiness is the complete dieback of the plant’s above-ground foliage, which should turn entirely yellow, wilt, and appear “dead.” This natural senescence signals that the plant has finished sending energy to the leaves and has diverted all resources to the underground tubers.
After the vines have completely died, the potatoes should remain undisturbed in the soil for an additional one to two weeks. This period is called the “setting” stage, during which the tuber’s skin thickens and hardens. This process protects the potato against bruising and decay during storage. Harvesting before the skin has fully set means the potatoes will be prone to damage and premature spoilage.
The Physical Harvest: Techniques for Digging
Proper preparation of the soil precedes the physical act of digging, helping to ensure the tubers are easily accessible and less prone to damage. It is beneficial to reduce or cease watering the plants entirely in the days leading up to the harvest, allowing the soil to dry out. This drying process helps the skins toughen further and makes the soil lighter and easier to work with.
When ready to dig, the correct tool and technique are paramount for avoiding accidental punctures, which render a potato unfit for long-term storage. A spading fork or a shovel should be inserted into the ground 12 to 18 inches away from the main stem to account for the spread of the tubers. The tool should be used to gently lift and loosen the entire clump of soil, rather than attempting to spear the plant directly.
Once the soil is loosened, the potatoes can be carefully lifted out of the ground by hand, shaking away the bulk of the loose dirt. It is important to search through the remaining soil carefully, as smaller tubers often detach and remain hidden. Freshly harvested Yukon Golds should not be washed, as excess moisture decreases their storage life and increases the risk of rot.
After they are out of the soil, an initial inspection must take place to separate the harvest into two groups. Any potato that is cut, bruised, or green from sun exposure must be set aside for immediate consumption, as these defects prevent proper curing and long-term preservation. The remaining undamaged tubers should be kept covered and out of direct light while still in the garden to prevent the development of chlorophyll and the bitter compound solanine.
Curing and Preparing for Storage
Once the sound, unblemished potatoes are brought in, they must undergo curing, a specialized healing process that prepares them for preservation. Curing allows minor abrasions on the skin to heal through suberization, which involves the formation of cork cells and further thickening the skin layer. This toughened outer layer acts as a barrier against moisture loss and infection during storage. Do not wash the tubers before this process, as added moisture will hinder the necessary skin-drying and healing.
The ideal environment for curing requires a temperature range of 50 to 60°F and a high relative humidity, specifically between 85 and 95 percent, for approximately two weeks. This setup encourages the formation of a protective layer of cork cells over any surface wounds. Placing the tubers in a dark, cool basement or garage, perhaps under a damp burlap sack or in perforated containers, helps maintain the necessary high-humidity conditions.
Following the curing period, the Yukon Golds are ready for long-term storage, which demands a consistently cooler and darker environment. The optimal storage temperature is slightly lower, ideally between 40 and 45°F, with humidity remaining high at about 90 to 95 percent. Storing them below 40°F can cause the potato starches to convert to sugar, resulting in an undesirable sweet taste.
The tubers should be kept in well-ventilated containers, such as wooden crates or mesh bags, and placed away from any ripening produce like apples or onions. These fruits release ethylene gas, which accelerates sprouting in potatoes, shortening their storage life. Maintaining these dark, cool conditions will help ensure the Yukon Golds remain fresh for several months.