Timing the harvest of homegrown potatoes in Ohio influences both the quality of the cooked product and its ability to store long-term. Unlike many garden vegetables where readiness is visible above ground, potato harvesting relies on monitoring the plant’s internal maturity and physical changes. Timing your harvest is a calculated choice between gathering small, thin-skinned tubers for immediate use or allowing the potatoes to fully mature and develop the thick skin necessary for extended storage.
Timing Based on Maturity
The calendar window for harvesting potatoes in Ohio extends from mid-July through mid-October, though the precise timing is determined by the gardener’s objective. If the goal is to harvest ‘new potatoes’—small, tender tubers with delicate skins—harvesting can begin relatively early. They are typically ready 55 to 70 days after planting, often coinciding with the plant’s flowering stage. Every potato variety will reach this immature size, making them perfect for immediate eating, but their thin skin means they must be consumed within days or weeks.
For maximum yield and long-term storage, the tubers must be allowed to reach full maturity. Storage potatoes require a full growing season of 90 to 120 days or more to reach their full size and develop a protective skin. Early season varieties like Yukon Gold mature toward the shorter end of that range, while late-season types such as Russets need the entire period. Relying on the plant’s visual cues is the most accurate way to ensure a mature harvest suitable for winter keeping.
Visual Cues for Harvest Readiness
The most reliable sign that a potato plant is nearing the end of its growth cycle is the complete die-back of the above-ground foliage. For storage potatoes, the lush green vines will begin to yellow, wither, and eventually turn brown and fall over, signaling that the plant has finished putting energy into the tubers. The skin of a fully mature potato must be “set” or hardened to prevent damage during digging and to inhibit moisture loss during storage.
After the foliage has completely died back, leave the tubers in the ground for an additional two to three weeks before digging. This waiting period allows the potato skin to develop suberin, a waxy compound that effectively seals the tuber and significantly extends its shelf life. To aid this process, gardeners should stop watering the potato patch one to two weeks before the planned harvest date. Harvesting new potatoes is signaled by the plant’s flowering, though the foliage should still be healthy and green at that time.
Digging and Preparing Potatoes for Storage
To safely remove mature potatoes from the soil, harvest on a dry day to prevent excess dirt from clinging to the tubers and reduce the risk of rot. Use a spading fork or shovel, inserting it well outside the projected cluster of potatoes to avoid piercing or slicing the tubers. After carefully lifting the soil, gently separate the potatoes from the root system and brush off any large clumps of dirt, but do not wash the potatoes.
Curing prepares the potatoes for long-term storage by healing minor cuts and abrasions and further thickening the skin. This requires placing the freshly dug tubers in a dark, well-ventilated area with high humidity, ideally around 80 percent, and a moderate temperature range of 60 to 65 degrees Fahrenheit for 10 to 14 days. Following the curing period, move the unwashed, undamaged potatoes to a permanent storage location that is dark, has high humidity, and maintains a cool temperature between 40 and 50 degrees Fahrenheit.