Warm-Season Vegetable

When to Plant Winter Squash

Long-season squash varieties (butternut, acorn, spaghetti, delicata) that store for months after fall harvest.

Sun

Full sun (6-8 hours)

Water

1-2 inches per week

Days to Harvest

85-120

Difficulty

beginner

Spacing

48"

Frost Tolerance

none

The Short Answer

Winter Squash are frost-sensitive and need warm soil and air temperatures to thrive. Start seeds indoors 3 weeks before your last frost date, then transplant outside 2 weeks after your last frost when soil temperatures reach at least 60°F. You can also direct sow seeds 2 weeks after your last frost. Enter your zip code on our homepage tool for exact dates.

How to Grow Winter Squash

Winter squash (butternut, acorn, spaghetti, delicata, hubbard) differs from summer squash in one critical way: you harvest it mature, with a hard rind, and it stores for months. The 'winter' name refers to when you eat it, not when you grow it — winter squash is planted in summer and harvested in fall. Cure in the sun for 10 days after harvest to harden the skin. Properly cured butternut stores 3-6 months at room temperature. Acorn squash has the shortest maturity (80 days) and is viable even in shorter-season gardens where butternut (100+ days) is a stretch.

Starting Seeds Indoors

Begin winter squash seeds indoors 3 weeks before your average last frost date. Seeds need soil temperatures of at least 60°F to germinate, which typically takes 5-10 days. Provide 12 hours of light per day using a south-facing window or grow lights.

Transplanting

Move seedlings outside 2 weeks after your last frost date, once soil temperatures reach 60°F. Harden off seedlings for 7 days before transplanting by gradually exposing them to outdoor conditions.

Direct Sowing

Winter Squash can be direct sown 2 weeks after your last frost date. Plant seeds 1" deep, spaced 48" apart.

Growing Tips

Cure harvested squash in sun for 10 days to harden skin. Properly cured butternut stores 3-6 months. Wait to harvest until skin resists thumbnail pressure and stem dries.

Companion Planting

Good companions:

Beans Corn Nasturtiums

Keep away from:

Potatoes

Winter Squash Planting Dates by State

Click your state for winter squash planting dates specific to your location:

Note: Planting dates are based on average frost dates from NOAA Climate Normals (30-year averages). Actual conditions vary year to year. Always check your local forecast before planting frost-sensitive crops.

Last reviewed: March 29, 2026