Winter squash are tender, warm-weather crops very similar to summer squashes. But, winter squashes—unlike summer squashes—must fully mature on the vine before harvest.
Summer squashes can be picked and eaten immature; they have a succulent texture. Winter squashes are drier and more fibrous than summer squashes.
Winter squashes include acorn, banana, buttercup, butternut, cushaw delicious, Hubbard, marrow, and pumpkin.
Sow winter squash indoor 4 to 3 weeks before the last expected frost in spring. Sow winter squash outdoors when the soil temperature has warmed to 70°F (21°C). Protect squash in the garden from cool temperatures with row covers.
Summer squash mature 60 to 100 frost-free days after sowing.
Sowing and Planting Tips:
- Grow winter squash from seeds or seedlings.
- Seed is viable for 6 years.
- Direct sow winter squash in the garden in spring after all danger of frost has passed and the soil has warmed to 70°F (21°C). In warm-winter regions, sow squash in midwinter for harvest in early summer.
- Winter squash seeds will not germinate at a soil temperature below 66°F (18°C).
- To start plants indoors, sow seed in peat pots 4 to 3 weeks before the last frost in spring. The indoor temperature should be 66°F to 85°F (18-29°C) until germination.
- Sow seed ½ to 1 inch (1.3-2.5 cm) deep.
- Seeds germinate in 4 to 10 days at 85°F (29°C) or warmer.
- Transplant winter squash into the garden after the soil has warmed to at least 70°F (21°C).
- Space plants in the garden 12 to 18 inches (30-45 cm) apart in all directions.
- Winter squash will benefit from the warm soil created by planting on hills or mounds; raise the soil 12 inches (30 cm) tall and 20 inches (50 cm) wide and grow individual plants on hills. Space hills 4 to 5 feet (1.2-1.5 m) apart.
- Water to keep the soil from drying.
- Fertilize with fish emulsion or a soluble complete fertilizer at half strength.
- Add aged compost to planting beds in advance of transplanting.
- Winter squash prefer a soil pH range of 5.5 to 6.8.
- Grow winter squash in full sun for best yield.
- Avoid planting winter squash where cucumbers or melons have grown recently.
- Common squash pest enemies include aphids, cucumber beetles, flea beetles, squash bugs, squash vine borers, slugs, and snails.
- Common diseases include bacterial wilt, fusarium wilt, downy mildew, powdery mildew, cucumber mosaic.
More tips at How to Grow Winter Squash.
Interplanting: Plant winter squash with bush beans, corn, dill, eggplant, lettuce, cucumbers, summer squash, and tomatoes.
Container Growing: Squash are not a good choice for container growing. They require significant room to spread and grow.
Recommended Planting Calendar:
- 4-3 weeks before the last frost in spring: start seed indoors for transplanting into the garden later.
- 2-3 weeks after the last frost in spring: transplant seedlings to the garden.
- 3 weeks after the last frost in spring: direct sow seed in the garden; minimum soil temperature 65°
Recommended Varieties: There many types and varieties of winter squash; here are a few:
- Acorn: acorn-shaped, dark green fruit to 2 pounds.
- Banana: smooth gray-green skin, light orange flesh to 18 inches long.
- Butternut: squat acorn shape; blackish-green rind with yellow-orange flesh.
- Cushaw: green-striped gourd to 15 inches long.
- Hubbard: bluish, gray, orange or dark green, smoot and warty skin.
- Pumpkins are winter squashes.
- Turban: bright-colored, turban-shaped shells 6 to 7 inches in diameter.
Botanical Names: Cucurbita maxima, Cucurbita moschata, Cucurbita pepo.
Winter squash are a members of the Cucurbitaceae family; other members cucumbers, melons, watermelon, and pumpkins.
More tips at Squash and Pumpkin Growing Tips.