Butternut Squash Gardening Guide: How to Grow Butternut Squash

Butternut squash (Cucurbita moschata) is a warm-season, annual plant that grows on a vine. When planted in the spring or just after the last frost, butternut squash plants produce fruits that start out green and mature into beige-colored gourds with thick, hard rinds. The soft, orange flesh has a nutty flavor reminiscent of pumpkin. Butternut squash has an oblong, hour-glass shape and seeds and pulp in its wide base.

Once your soil temperature reaches 60 degrees Fahrenheit and there's no longer any danger of frost, it’s planting time. Follow these steps to plant butternut squash seeds:

• Start the seeds inside. If the warm season in your area is short, you can start your seeds indoors six weeks before the expected last frost. Plant seeds in well-draining soil in a sunny window or greenhouse. Harden them off before transplanting the seedlings to an outdoor location after the last frost.
• Choose a sunny, well-draining spot. Whether you're planting your seeds directly in the ground or in a raised bed, butternut squash will do best in any area that gets full sun. Butternut squash prefers well-draining soil that’s rich in organic matter.
• Make a hill. Just like with most vining vegetables, butternut squash plants require you to mound the soil before planting. Gather soil into a mound or small hill about 18 inches tall before sowing your seeds.
• Bury seeds just below the soil’s surface. Sow seeds in groups of four to five at a depth of half an inch to an inch. Spacing the seeds about four inches apart will prevent overcrowding as the plants grow.
• Water the seedlings regularly. Butternut squash seeds require consistently damp soil until they establish themselves. Keep the soil moist but not soaking, and the seeds should sprout in about 10 days.
• Thin your seedlings. Once your seedlings sprout, thin them out to the recommended spacing indicated on the seed packet.

Butternut squash has a long growing season of about 110 days. Follow a few care tips to keep these plants healthy all season long.

• Fertilize your plants. As heavy feeders, butternut squash responds well to fertilizer. In addition to planting your seeds in soil that's rich in organic matter, fertilizing your plants with a compost tea or liquid fertilizer every two to three weeks will help keep them healthy. Alternatively, you can add compost or manure to your soil hills in the middle of the growing season.
• Defend squash from pests. One insect loves to infect squash so much that it takes its name from the plant: squash bugs. Squash bugs are dark grey or dark brown in color with a thin abdomen resembling a fingernail. They tend to target young seedlings and flowering plants. They damage the leaves by sucking out the sap, causing the leaves to wilt. Your best chance at defending your plants from these pests is to check under their leaves for eggs and remove them with a damp cloth.
• Space them out to prevent disease. Squash plants are prone to powdery mildew—a fungus disease that turns the leaves grayish-white. Proper spacing and thinning will help increase airflow around the plant and reduce its chances of getting the disease.
• Care for the leaves. Butternut squash plants require plenty of water, but their leaves prefer to stay dry. Water the base of the plant and avoid spraying the leaves.

Winter squash varieties have hard, thick rinds, making it possible to store them throughout the winter. By contrast, summer squashes like zucchini have soft skins and will not keep for long. Butternut squash is one of several varieties of winter squash. Other varieties include acorn squash, delicata, Hubbard, kabocha, Waltham butternut, and spaghetti squash. All of these squash varieties grow edible male flowers and female flowers on the same plant.

Grow your own garden with Ron Finley, the self-described "Gangster Gardener." Get the MasterClass Annual Membership and learn how to cultivate fresh herbs and vegetables, keep your house plants alive, and use compost to make your community—and the world—a better place.