Root Vegetable

When to Plant Radishes in Delaware

The fastest vegetable in the garden — some varieties are ready in just 25 days. Perfect for impatient gardeners and kids.

The Short Answer

In Delaware, soil conditions are an important factor for radishes. Sandy soils in south, clay loam in north. Generally well-drained. Slightly acidic. Direct sow 4 weeks before your last frost date. Radishes can also be planted in fall, 6 weeks before your first frost.

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

Radishes Planting Schedule for Delaware

Northern Delaware (Zones 7a)

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

Direct Sow

4 wks before frost

Fall Planting

6 wks before first frost

Southern Delaware (Zones 7b)

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

Direct Sow

4 wks before frost

Fall Planting

6 wks before first frost

Growing Radishes in Delaware

Radishes in Delaware's Climate

Radishes are the instant-gratification crop of spring. Direct sow 4 weeks before last frost and succession plant every 2 weeks through May. They bolt and turn pithy once temperatures exceed 80°F consistently. Resume sowing in September for fall harvest. Great for kids and first-time gardeners.

Soil Considerations for Delaware

Sandy soils in south, clay loam in north. Generally well-drained. Slightly acidic. Loose, well-drained soil is especially important for radishes since the edible portion grows underground. If your soil is heavy clay, consider raised beds.

Delaware Climate & Growing Season

Moderate climate with maritime influence. Good growing conditions for a wide range of vegetables. Radishes can handle frost well, which is an advantage in Delaware's climate. You can push planting dates earlier in spring and extend into fall.

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 radishes — but radishes handle frost well, so the timing difference is less critical.

Growing Tips

Don't let them stay in the ground too long — they get pithy and hot. Succession plant every 2 weeks for continuous harvest.

Companion Planting

Plant radishes alongside these companions for better growth:

Peas Lettuce Carrots Spinach

The Bottom Line

Radishes 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