Warm-Season Vegetable

When to Plant Squash (Summer) in Hawaii

Zucchini and yellow squash are the garden's most generous producers. You'll be sharing with neighbors by midsummer.

The Short Answer

In Hawaii, squash (summer) planting dates vary by region. In Coastal Hawaii, your average last frost is around None, while Upcountry/Mountain sees its last frost around Rare. Since squash (summer) are frost-sensitive, start seeds indoors 3 weeks before your last frost, then transplant outside 2 weeks after frost danger has passed. Volcanic soils — extremely fertile but can be acidic. Excellent drainage on slopes. Varies dramatically by island and...

Hawaii Frost Dates

Your planting dates depend on which part of Hawaii you're in. Here are the frost date ranges by region:

Region Zones Last Frost (Spring) First Frost (Fall)
Coastal Hawaii 11a, 11b, 12a, 12b, 13a None None
Upcountry/Mountain 10a, 10b, 11a Rare Rare

Squash (Summer) Planting Schedule for Hawaii

Coastal Hawaii (Zones 11a, 11b, 12a, 12b, 13a)

Average last frost: None · Average first frost: None

Start Seeds Indoors
3 wks before frost
Transplant Outside
2 wks after frost
Direct Sow
2 wks after frost

Upcountry/Mountain (Zones 10a, 10b, 11a)

Average last frost: Rare · Average first frost: Rare

Start Seeds Indoors
3 wks before frost
Transplant Outside
2 wks after frost
Direct Sow
2 wks after frost

Growing Squash (Summer) in Hawaii

Squash (Summer) in Hawaii's Climate

Squash grows during the cooler months in subtropical zones. Plant from September through February. Summer squash matures quickly enough to succeed even in Florida's compressed cool window. Pickle worm is a devastating fruit pest in the Deep South that northern growers never encounter.

Soil Considerations for Hawaii

Volcanic soils — extremely fertile but can be acidic. Excellent drainage on slopes. Varies dramatically by island and elevation. Make sure soil has warmed to at least 60°F before planting squash (summer) outside.

Hawaii Climate & Growing Season

Tropical. Year-round growing season at lower elevations. Elevation creates microclimates. Plant warm-season crops anytime. Squash (Summer) cannot tolerate any frost, so wait until all frost danger has passed before transplanting outside. Watch local forecasts carefully in spring.

Growing season length varies across Hawaii: Coastal Hawaii (11a, 11b, 12a, 12b, 13a) has a last frost around None, while Upcountry/Mountain (10a, 10b, 11a) sees frost end around Rare. This difference matters for squash (summer) — transplant timing shifts by several weeks across the state.

Growing Tips

Harvest when fruits are 6-8 inches long for best flavor. Larger squash become seedy and tough.

Companion Planting

Plant squash (summer) alongside these companions for better growth:

Corn Beans Nasturtiums

Keep squash (summer) away from:

Potatoes

The Bottom Line

Squash (Summer) can be grown successfully across Hawaii, but your exact planting dates depend on which region you're in. Coastal Hawaii gardeners should plan around a None last frost, while those in Upcountry/Mountain can typically plant later. For exact dates based on your zip code, use our free planting date finder.

Related Guides

Squash (Summer) Growing Guide National planting guide with all states Hawaii Planting Calendar All plants for Hawaii Squash (Summer) in Alabama Alabama planting dates Squash (Summer) in Alaska Alaska planting dates Squash (Summer) in Arizona Arizona planting dates Squash (Summer) in Arkansas Arkansas planting dates
Note: All dates are based on NOAA 30-year Climate Normals and represent historical averages, not predictions for any specific year. Always check your local weather forecast before planting frost-sensitive crops. Learn about our data sources.

Last reviewed: March 29, 2026

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