Harvesting and storing potatoes effectively is the final stage of the growing season, directly impacting the yield and longevity of your crop. Maximizing the quality of your potatoes for long-term use relies on precision, from recognizing when the tubers are ready to employing the right tools for a gentle lift. A successful harvest ensures that the potato skins are properly set for protection, minimizing damage and preparing them for the essential post-harvest curing phase.
Determining the Optimal Harvest Time
The correct harvest time is determined by the intended use of the potatoes, specifically whether they are destined for immediate consumption or long-term storage. Potatoes harvested early, known as “new potatoes,” are small with delicate, thin skins and are ready about two to three weeks after the plant begins flowering. These young tubers are best consumed quickly because their fragile skins do not offer sufficient protection for extended keeping.
For potatoes meant for storage, the key indicator is the complete die-back of the plant’s foliage. Once the leafy green vines turn yellow, then brown, and wither away entirely, the plant is redirecting its energy to finalize tuber development underground. This signals that the tubers have reached their full size and are beginning the maturation process.
It is critical to wait approximately two weeks after the foliage has fully died back before digging the potatoes. This waiting period allows the potato’s skin to “set,” or thicken and harden, which prevents moisture loss and resists damage during handling. If the skin easily sloughs off when gently rubbed, the tuber is not ready, and you should wait a few more days.
Tools and Techniques for Digging
Selecting the right tool for digging is important for avoiding cuts and bruises that can compromise the potato’s storage life. A garden fork or a specialized potato digging fork is strongly preferred over a shovel or spade because the rounded tines are less likely to slice into the tubers. The wide surface of a shovel makes accidental piercing or slicing of the potatoes far more common.
Begin the digging process by inserting the fork into the soil well outside the expected perimeter of the plant, typically about 8 to 12 inches away from the main stem. This distance helps ensure you lift the entire cluster of tubers rather than spearing or scraping them. Gently push down on the fork’s handle to lift the soil and the potatoes contained within, rather than using a sharp prying motion.
For potatoes grown in containers or raised beds, the technique is simpler and less damaging. The entire contents of the container can often be tipped out onto a tarp or wheelbarrow, making it easy to sift through the loose soil by hand. Regardless of the method, handle the newly harvested potatoes with care to prevent bruising, as damaged areas are entry points for rot-causing pathogens.
Curing and Proper Storage
After harvesting, potatoes must undergo a two-step process: curing, followed by long-term storage. Curing is a short period, typically one to two weeks, where the potatoes are held in a dark, humid environment with moderate temperatures, ideally between 50 and 60°F. This process allows minor wounds to heal and causes the outer skin layer to dry and thicken, significantly extending the storage potential.
Following the curing period, the potatoes are ready for long-term storage, which requires a cool, dark, and well-ventilated space. The ideal temperature range for long-term keeping is consistently between 40 and 50°F, such as in an insulated garage or a cool basement. Temperatures below this range can cause the potato’s starch to convert into sugar, resulting in an undesirable sweet flavor when cooked.
It is important to store the tubers away from any light source, as exposure causes the skin to turn green, signaling the presence of the toxic compound solanine. Potatoes should be kept in breathable containers like burlap sacks, cardboard boxes, or crates to allow for air circulation, preventing the buildup of moisture that encourages sprouting and decay. Always inspect the potatoes before storage and remove any with deep cuts or signs of disease, using those damaged tubers first.