Herb

When to Plant Basil in Delaware

The king of herbs. Basil and tomatoes are best friends in the garden and in the kitchen.

The Short Answer

In Delaware, plant basil based on your regional frost dates. Northern Delaware has a last frost around Apr 10 - Apr 25, while Southern Delaware sees frost end around Apr 1 - Apr 15. Moderate climate with maritime influence. Good growing conditions for a wide range of vegetables.

Delaware Frost Dates

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

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

Basil Planting Schedule for Delaware

Northern Delaware (Zones 7a)

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

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

Southern Delaware (Zones 7b)

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

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

Growing Basil in Delaware

Basil in Delaware's Climate

Your summer warmth grows excellent basil from transplant through first frost. Start indoors 6 weeks before last frost or buy transplants. Basil peaks in July-August when heat intensifies the essential oils. Succession plant or pinch flowers to keep production going. Plant near tomatoes — the classic companion pairing that works in the kitchen as well as the garden.

Soil Considerations for Delaware

Sandy soils in south, clay loam in north. Generally well-drained. Slightly acidic. Make sure soil has warmed to at least 60°F before planting basil outside.

Delaware Climate & Growing Season

Moderate climate with maritime influence. Good growing conditions for a wide range of vegetables. Basil 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 Delaware: Northern Delaware (7a) has a last frost around Apr 10 - Apr 25, while Southern Delaware (7b) sees frost end around Apr 1 - Apr 15. This difference matters for basil — transplant timing shifts by several weeks across the state.

Growing Tips

Pinch off flower buds to keep leaves producing. Harvest from the top down, cutting just above a leaf pair. Succession plant for season-long supply.

Companion Planting

Plant basil alongside these companions for better growth:

Tomatoes Peppers Oregano

Keep basil away from:

Sage

The Bottom Line

Basil can be grown successfully across Delaware, but your exact planting dates depend on which region you're in. Northern Delaware gardeners should plan around a Apr 10 - Apr 25 last frost, while those in Southern Delaware 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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