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When to Plant Watermelon in Hawaii

Watermelon is a sprawling vine crop that produces sweet, juicy fruits in hot weather. Varieties range from personal-sized icebox types to 50-pound giants.

Hawaii spans USDA hardiness zones 11a, 11b (with planting data available), so planting dates vary by your location within the state. Click your zone below for the most accurate dates.

Find Your County

Click your county for exact Watermelon planting dates based on your local frost dates.

Hover over a county to see details. Click to view planting guide.

Watermelon Planting Calendar for Hawaii

Zone 11a ~364 day growing season · Full guide →

Last frost: January 1 · First frost: December 31 · 364 day season

Activity When Date Range
Start Indoors December 4 Dec 4 – Dec 18
Transplant Outdoors January 8 Jan 8 – Jan 22
Direct Sow January 1 Jan 1 – Jan 22
Harvest March 19 Mar 19 – May 7
Zone 11b ~364 day growing season · Full guide →

Last frost: January 1 · First frost: December 31 · 364 day season

Activity When Date Range
Start Indoors December 4 Dec 4 – Dec 18
Transplant Outdoors January 8 Jan 8 – Jan 22
Direct Sow January 1 Jan 1 – Jan 22
Harvest March 19 Mar 19 – May 7

Growing Tips for Hawaii

Start seeds indoors 3-4 weeks early or direct sow after soil is warm. Plant on mounds with plenty of space. Check ripeness by looking for a yellow ground spot and dull thump when tapped.

Frequently Asked Questions

When should I plant Watermelon in Hawaii?

Planting dates for Watermelon in Hawaii depend on your USDA zone. Hawaii spans zones 11a, 11b. Check the planting calendar above for your specific zone's frost dates and planting windows.

What zone is Hawaii for planting?

Hawaii contains USDA hardiness zones 11a, 11b. Your specific zone depends on your location within the state — northern and higher-elevation areas are in colder zones, while southern and coastal areas are warmer.

Data sources: USDA Plant Hardiness Zone Map (2023), NOAA 30-Year Climate Normals, University Cooperative Extension planting guides. Last updated: April 2026.