Growing potatoes in New York requires precise timing due to the state’s diverse climate and multiple hardiness zones. Relying on a single calendar date is ineffective. Successful planting depends on observing specific environmental conditions, particularly the temperature of the soil in your microclimate. This attention ensures the seed potatoes sprout vigorously and avoid rot in cold, wet ground.
Determining the Optimal Planting Window
The optimal planting time is determined by the soil temperature and the average last expected frost date, not the calendar. Potatoes are a cool-weather crop that can tolerate light frost, but the seed piece is vulnerable to rotting if planted too early in cold, saturated earth. While the absolute minimum temperature for planting is 40°F, waiting until the soil consistently registers 45°F to 50°F promotes faster sprouting and reduces the risk of failure.
Warmer areas, such as Long Island and the lower Hudson Valley, often plant earliest, typically in early to mid-April. Conversely, Upstate or Western New York, which fall into colder hardiness zones, generally must wait until late April or the first week of May. Planting two to four weeks before the last anticipated spring frost date balances the need for an early start with the danger of cold ground.
Preparing Seed Potatoes and Soil
For a strong start, use certified, disease-free seed potatoes, which are guaranteed to be free of common viruses and pathogens that can severely impact yield. A beneficial preparation step is “chitting,” which involves encouraging the tubers to sprout eyes before planting.
To chit potatoes, place the seed tubers in a single layer in a light, cool, frost-free location for four to six weeks until short, sturdy, green sprouts develop. Larger seed potatoes should be cut into 1.5 to 2-ounce pieces, ensuring each piece contains at least one or two “eyes.” After cutting, allow the pieces to cure for two to three days in a well-ventilated space to form a protective layer, which helps prevent rot.
The soil needs to be loose, deep, and well-draining, with a high content of organic matter. Potatoes grow best in slightly acidic soil, ideally with a pH range of 5.8 to 6.5, though a lower pH of 4.8 to 5.5 may be preferable if potato scab disease is a concern. Incorporating well-aged compost or manure into the soil the previous fall is the best practice, as fresh manure can introduce pathogens that cause scab.
Planting Depth Spacing and Hilling
Planting involves creating a shallow trench, typically four to six inches deep. Place the prepared seed pieces cut-side down, with the sprouted eyes facing upward, along the bottom of the trench. Space the pieces 10 to 12 inches apart to give the plants room to develop tubers. After placement, cover the seed with only about three inches of soil, leaving the trench partially unfilled.
Hilling, or mounding soil around the stems, is a necessary step in potato cultivation. Potatoes form new tubers along the underground stem, so adding soil encourages more of the stem to produce storage organs. When the emerging foliage reaches six to eight inches tall, gently draw loose soil up around the plant until only the top leaves are exposed. Repeat this process every few weeks as the plant grows, eventually creating a substantial mound around the base. This mound shields developing tubers from sunlight, preventing them from turning green and producing the mildly toxic compound solanine.