Annual Flower

When to Plant Sunflowers in Hawaii

Few things bring more joy than a row of sunflowers turning their faces to the sun. Easy, dramatic, and pollinator-friendly.

The Short Answer

In Hawaii, plant sunflowers based on your regional frost dates. Coastal Hawaii has a last frost around None, while Upcountry/Mountain sees frost end around Rare. Tropical. Year-round growing season at lower elevations. Elevation creates microclimates. Plant warm-season crops...

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

Sunflowers Planting Schedule for Hawaii

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

Average last frost: None · Average first frost: None

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

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

Average last frost: Rare · Average first frost: Rare

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

Growing Sunflowers in Hawaii

Sunflowers in Hawaii's Climate

Sunflowers handle extreme heat well — they're one of the few ornamental flowers that actually improve with more sun and warmth. In the desert, plant in early spring before extreme heat arrives. In subtropical Florida, sunflowers grow best during the drier, cooler months from October through March.

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 55°F before planting sunflowers outside.

Hawaii Climate & Growing Season

Tropical. Year-round growing season at lower elevations. Elevation creates microclimates. Plant warm-season crops anytime. Sunflowers 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 sunflowers — transplant timing shifts by several weeks across the state.

Growing Tips

Direct sow is preferred — sunflowers don't love transplanting. Succession plant every 2 weeks for blooms all summer.

Companion Planting

Plant sunflowers alongside these companions for better growth:

Cucumbers Squash Corn

Keep sunflowers away from:

Potatoes

The Bottom Line

Sunflowers 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.
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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