Warm-Season Vegetable

When to Plant Watermelon in Oklahoma

The ultimate summer treat. Watermelons need heat, space, and patience — but the payoff is pure joy.

The Short Answer

In Oklahoma, watermelon planting dates vary by region. In Northern Oklahoma, your average last frost is around Apr 5 - Apr 20, while Southern Oklahoma sees its last frost around Mar 15 - Apr 1. Since watermelon are frost-sensitive, start seeds indoors 3 weeks before your last frost, then transplant outside 2 weeks after frost danger has passed. Red clay soils common. Alkaline in west. Rich prairie soils in east. Wind erosion in western panhandle.

Oklahoma Frost Dates

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

Region Zones Last Frost (Spring) First Frost (Fall)
Northern Oklahoma 6b, 7a Apr 5 - Apr 20 Oct 15 - Nov 1
Central Oklahoma 7a, 7b Mar 25 - Apr 10 Oct 25 - Nov 10
Southern Oklahoma 7b Mar 15 - Apr 1 Nov 1 - Nov 15

Watermelon Planting Schedule for Oklahoma

Northern Oklahoma (Zones 6b, 7a)

Average last frost: Apr 5 - Apr 20 · Average first frost: Oct 15 - Nov 1

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

Central Oklahoma (Zones 7a, 7b)

Average last frost: Mar 25 - Apr 10 · Average first frost: Oct 25 - Nov 10

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

Southern Oklahoma (Zones 7b)

Average last frost: Mar 15 - Apr 1 · Average first frost: Nov 1 - Nov 15

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

Growing Watermelon in Oklahoma

Watermelon in Oklahoma's Climate

Watermelon is a natural fit for your warm climate. The long, hot season produces the sweetest, largest melons. Start transplants early for a long harvest. Texas, Georgia, and the Carolinas are premier watermelon territory. Deep watering during fruit development and reducing water near harvest concentrates sweetness.

Soil Considerations for Oklahoma

Red clay soils common. Alkaline in west. Rich prairie soils in east. Wind erosion in western panhandle. Make sure soil has warmed to at least 70°F before planting watermelon outside.

Oklahoma Climate & Growing Season

Hot summers. Severe thunderstorms and tornado risk. Good growing season length. Windy — windbreaks help gardens. Watermelon 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 Oklahoma: Northern Oklahoma (6b, 7a) has a last frost around Apr 5 - Apr 20, while Southern Oklahoma (7b) sees frost end around Mar 15 - Apr 1. This difference matters for watermelon — transplant timing shifts by several weeks across the state.

Growing Tips

Black plastic mulch warms soil faster. Check ripeness by looking for a yellow ground spot and listening for a hollow thump.

Companion Planting

Plant watermelon alongside these companions for better growth:

Corn Sunflowers Marigolds

Keep watermelon away from:

Potatoes

The Bottom Line

Watermelon can be grown successfully across Oklahoma, but your exact planting dates depend on which region you're in. Northern Oklahoma gardeners should plan around a Apr 5 - Apr 20 last frost, while those in Southern Oklahoma can typically plant earlier. For exact dates based on your zip code, use our free planting date finder.

Related Guides

Watermelon Growing Guide National planting guide with all states Oklahoma Planting Calendar All plants for Oklahoma Watermelon in Alabama Alabama planting dates Watermelon in Alaska Alaska planting dates Watermelon in Arizona Arizona planting dates Watermelon 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

Ready to Start Planting?

Enter your zip code and pick your plant. We'll tell you exactly when to plant, start seeds, and harvest — based on where you live.

Find Your Planting Dates