Warm-Season Vegetable

When to Plant Watermelon in Kansas

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

The Short Answer

In Kansas, watermelon planting dates vary by region. In Northern Kansas, your average last frost is around Apr 20 - May 5, while Southern Kansas sees its last frost around Apr 1 - Apr 15. Since watermelon are frost-sensitive, start seeds indoors 3 weeks before your last frost, then transplant outside 2 weeks after frost danger has passed. Prairie soils in east — rich and deep. More alkaline and thinner soils in west. Wind erosion can be an issue.

Kansas Frost Dates

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

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

Watermelon Planting Schedule for Kansas

Northern Kansas (Zones 5b, 6a)

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

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

Central Kansas (Zones 6a, 6b)

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

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

Southern Kansas (Zones 6b, 7a)

Average last frost: Apr 1 - Apr 15 · 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

Growing Watermelon in Kansas

Watermelon in Kansas's Climate

Watermelon is achievable with transplants and short-to-medium season varieties. Start indoors 3 weeks before last frost. Black plastic mulch warms soil for earlier transplanting. Crimson Sweet (80 days) is the most popular variety. Your warm July-August provides the sustained heat watermelons need for sweetness.

Soil Considerations for Kansas

Prairie soils in east — rich and deep. More alkaline and thinner soils in west. Wind erosion can be an issue. Make sure soil has warmed to at least 70°F before planting watermelon outside.

Kansas Climate & Growing Season

Hot summers with strong winds. Severe thunderstorms and hail risk. Drier in the west. Good growing conditions for heat-loving crops. 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 Kansas: Northern Kansas (5b, 6a) has a last frost around Apr 20 - May 5, while Southern Kansas (6b, 7a) sees frost end around Apr 1 - Apr 15. 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 Kansas, but your exact planting dates depend on which region you're in. Northern Kansas gardeners should plan around a Apr 20 - May 5 last frost, while those in Southern Kansas can typically plant earlier. 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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