Warm-Season Vegetable

When to Plant Watermelon in New Jersey

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

The Short Answer

In New Jersey, watermelon planting dates vary by region. In Northern New Jersey, your average last frost is around Apr 20 - May 5, while Southern New Jersey 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. Sandy soils in Pine Barrens. Clay in north. Acidic in south. Rich loam in central agricultural areas. The Garden State...

New Jersey Frost Dates

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

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

Watermelon Planting Schedule for New Jersey

Northern New Jersey (Zones 6a, 6b)

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

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

Central New Jersey (Zones 6b, 7a)

Average last frost: Apr 10 - Apr 25 · 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

Southern New Jersey (Zones 7a, 7b)

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

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

Growing Watermelon in New Jersey

Watermelon in New Jersey'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 New Jersey

Sandy soils in Pine Barrens. Clay in north. Acidic in south. Rich loam in central agricultural areas. The Garden State for good reason. Make sure soil has warmed to at least 70°F before planting watermelon outside.

New Jersey Climate & Growing Season

Moderate climate with maritime influence. Good growing season. Four seasons. Excellent for a wide range of 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 New Jersey: Northern New Jersey (6a, 6b) has a last frost around Apr 20 - May 5, while Southern New Jersey (7a, 7b) 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 New Jersey, but your exact planting dates depend on which region you're in. Northern New Jersey gardeners should plan around a Apr 20 - May 5 last frost, while those in Southern New Jersey 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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