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Can You Grow Butternut Squash in Iowa?

US · USDA Zone 5a · zones 4a, 4b, 5a, 5b

Grows well here

Butternut squash thrives here with warm, frost-free summers and full sun.

Plant zones

3a–10b

Iowa last frost

mid-April

Iowa first frost

mid-October

Days to harvest

100–120 days

When to plant Butternut Squashes in Iowa

Start indoors

Mar 18

Transplant

Apr 15

Harvest

Jul 24 – Aug 13

Dates are approximate, based on Iowa's average frost dates. Your exact yard may vary by microclimate.

About Butternut Squash

Butternut squash is the most popular winter squash — sweet, smooth, and superb for storage. A vigorous vining plant that needs warm weather and room to sprawl.

Direct sow after last frost or start indoors 3-4 weeks earlier. Harvest when skin turns tan and hard. Cure 1-2 weeks in a warm spot before storing in a cool dry place.

Full butternut squash growing guide →

Gardening in Iowa

Iowa has a humid continental climate with cold winters and warm summers. Most of the state is Zone 5a-5b. Excellent for cool-season crops and hardy fruits.