Warm-Season Vegetable

When to Plant Watermelon in Missouri

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

The Short Answer

In Missouri, watermelon planting dates vary by region. In Northern Missouri, your average last frost is around Apr 20 - May 5, while Southern Missouri 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. Rich loess soils along Missouri River. Rocky Ozark soils in south. Heavy clay common. Generally fertile.

Missouri Frost Dates

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

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

Watermelon Planting Schedule for Missouri

Northern Missouri (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 Missouri (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 Missouri (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 Missouri

Watermelon in Missouri'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 Missouri

Rich loess soils along Missouri River. Rocky Ozark soils in south. Heavy clay common. Generally fertile. Make sure soil has warmed to at least 70°F before planting watermelon outside.

Missouri Climate & Growing Season

Continental climate. Hot, humid summers. Four seasons. Good growing season in most of state. 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 Missouri: Northern Missouri (5b, 6a) has a last frost around Apr 20 - May 5, while Southern Missouri (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 Missouri, but your exact planting dates depend on which region you're in. Northern Missouri gardeners should plan around a Apr 20 - May 5 last frost, while those in Southern Missouri 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 Missouri Planting Calendar All plants for Missouri 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

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