Growing potatoes starts with the timing of your purchase. Seed potatoes are specialized, certified, disease-free tubers, distinct from grocery store varieties often treated with growth inhibitors. Securing these planting pieces at the appropriate time maximizes both yield and variety selection for a successful harvest.
Determining the Right Time to Buy
The purchasing calendar depends on your local climate and the date of your last expected hard frost. The ideal time to buy is approximately six to eight weeks before your anticipated planting date. This timing is typically two to four weeks before the last frost. Planting can occur once the soil temperature consistently reaches 45 degrees Fahrenheit, though 50°F is better for quick emergence.
For gardeners in most temperate regions, the prime purchasing window opens in late January and extends through March. This early purchase allows sufficient time for chitting, a pre-planting process. Chitting allows the tuber to break dormancy and begin developing sprouts before planting.
Calculate your purchase date backward from your expected planting time to ensure adequate preparation. Waiting until the soil is ready to plant is too late to achieve the benefits of an early start. Suppliers generally begin shipping in the late winter to accommodate this preparatory period.
Why Buying Early Ensures Success
Purchasing early is a strategic decision driven by market availability and tuber quality. Certified seed potatoes are grown in limited supply, so buying early guarantees access to the widest selection of varieties before suppliers sell out. This selection includes early, mid, and late-season varieties, as well as unique heirloom or specialty cultivars.
The earlier stock received is generally fresher, having been stored under optimal, cold conditions to keep them dormant. As the season progresses, seed potatoes held in warehouses or garden centers may sprout prematurely due to warmer ambient temperatures. These early, weak sprouts easily break off during handling, wasting the tuber’s energy reserves and diminishing its growing potential.
Proper Storage and Pre-Planting Preparation
Once acquired, handle the seed potatoes correctly to maintain dormancy until chitting begins. Initially, store the tubers in a cool, dark, dry, and frost-free environment, ideally between 34 to 38 degrees Fahrenheit. These conditions slow the tuber’s metabolic rate, preventing premature sprouting.
Approximately four to six weeks before planting, begin chitting by encouraging the development of short, sturdy sprouts. Move the seed potatoes to a cool, well-lit location with temperatures between 50 and 55 degrees Fahrenheit. Placing the tubers in a single layer, such as in an egg carton with the blunt, “rose” end facing up, ensures even light exposure.
Exposure to light at this lower temperature prevents the sprouts from becoming long, pale, and weak, a condition known as etiolation. Aim for the development of compact, dark green or purplish sprouts, which are structurally strong and will not easily snap off during planting. These prepared tubers give your crop a significant head start, leading to earlier emergence and a higher overall yield.