Growing sweet potatoes in Minnesota may seem like a daunting task due to the state’s short growing season and cooler climate. However, with careful planning and proper techniques, you can enjoy a bountiful harvest of this nutritious and versatile tuber. In this article, we will explore everything you need to know about growing sweet potatoes in Minnesota—from selecting the right varieties to harvesting your crop.
Sweet potatoes (Ipomoea batatas) are not only delicious but also packed with nutrients. They are rich in vitamins A and C, fiber, and antioxidants. Unlike regular potatoes, sweet potatoes thrive in warm temperatures and require a longer growing season. Typically, sweet potatoes need at least 90 to 120 days of warm weather to fully mature.
In Minnesota, where the growing season is relatively short, careful timing and selection of the right varieties are crucial for successfully cultivating sweet potatoes.
When it comes to choosing sweet potato varieties suitable for Minnesota’s climate, it’s important to select those that mature quickly. Here are some recommended varieties:
Beauregard: This is one of the most popular varieties among home gardeners, known for its high yield and resistance to disease. Beauregard can be harvested in approximately 90 days.
Georgia Jet: Another fast-maturing variety, Georgia Jet is known for its excellent flavor and texture. It typically matures in around 90 days as well.
Covington: This variety not only offers high yields but also has good storage potential. It matures in about 100 days.
O’Henry: For gardeners looking for white-fleshed sweet potatoes, O’Henry is an excellent choice that matures in roughly 100 days.
By choosing early-maturing varieties, you can increase your chances of a successful harvest before the onset of frost.
Given Minnesota’s shorter growing season, starting sweet potatoes indoors can give them a head start. Here’s how to do it:
Purchase certified disease-free sweet potato slips from a reputable nursery or garden center. You can also grow your own slips by starting with whole sweet potatoes from the grocery store or farmers’ market.
If you’re using whole potatoes to grow slips, place them in a container with water—half submerged—and keep them in a warm, sunny location. After a few weeks, you will begin to see sprouts develop from the ‘eyes’ of the potato.
Once the sprouts have reached about 6 inches in height, carefully twist them off the parent potato and place them in water until they develop roots. This usually takes about a week.
Start your slips about 6-8 weeks before the last expected frost date for your area. In Minnesota, this typically falls between mid-May and early June.
To ensure an optimal growing environment for your sweet potatoes, follow these steps to prepare your garden bed:
Sweet potatoes thrive in full sun, so select a spot that receives at least 6-8 hours of direct sunlight each day.
Sweet potatoes prefer loose, well-draining soil rich in organic matter. Aim for slightly acidic soil with a pH between 5.8 and 6.2.
Soil Amendments: Incorporate compost or well-rotted manure into the soil before planting. This will enhance soil fertility and improve drainage.
Tilling: Loosen the soil to a depth of at least 12 inches by tilling or turning it over with a garden fork.
In areas with heavy clay soil or poor drainage, consider creating raised beds filled with quality soil mix to promote better root development.
Once your slips are ready and the garden bed is prepared, it’s time to plant:
Wait until all danger of frost has passed and soil temperatures are consistently above 60°F (15°C). This is typically around late May in Minnesota.
Depth: Plant sweet potato slips deep enough so that the lower leaves are just above the soil level.
Spacing: Space slips approximately 12-18 inches apart in rows that are spaced about 3 feet apart to allow ample room for growth.
Proper care throughout the growing season is essential for healthy plants and a good harvest.
Sweet potatoes require consistent moisture but do not tolerate waterlogged conditions. Water regularly throughout their growing season—aiming for about an inch of water per week (including rainfall).
Use a balanced fertilizer at planting time or as soon as sprouts begin to emerge. Avoid high-nitrogen fertilizers as they can promote leaf growth at the expense of tuber development.
Keep weeds at bay using mulch or by hand-pulling as needed. Weeds compete for nutrients and water that your sweet potato plants need to thrive.
Common pests include aphids and weevils; however, healthy plants generally resist infestations better than stressed ones. You can use insecticidal soap or neem oil if infestations occur.
Sweet potatoes are typically ready for harvest when they reach maturity—usually around late September to early October in Minnesota before frost sets in.
Watch for signs such as yellowing leaves or when vines start dying back—this indicates that tubers are ready for harvesting.
Use a spading fork or shovel carefully around the base of each plant to loosen the soil without damaging tubers. Gently lift each plant out of the ground.
After harvesting, curing your sweet potatoes will improve flavor and storage life:
Curing Process: Place harvested sweet potatoes in a warm (around 85°F/29°C), humid environment for about two weeks.
Storage Conditions: Once cured, store sweet potatoes in a cool (55°F/13°C), dark place with good ventilation—such as a basement or root cellar—to maximize their shelf life.
Growing sweet potatoes in Minnesota may require some extra effort due to climate challenges, but it is entirely feasible with proper planning and care. By selecting suitable varieties, starting slips indoors, preparing your garden bed thoughtfully, and following best practices through planting and harvesting, you can enjoy delicious homegrown sweet potatoes even in this northern state.
With their versatility in cooking—from roasting and mashing to using them in soups—sweet potatoes provide not just nourishment but also satisfaction that comes from growing your own food sustainably!