Root Vegetable

When to Plant Sweet Potatoes in Delaware

Not related to regular potatoes at all. Sweet potatoes need heat and a long growing season but reward with incredible harvests.

The Short Answer

In Delaware, soil conditions are an important factor for sweet potatoes. Sandy soils in south, clay loam in north. Generally well-drained. Slightly acidic.

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

Sweet Potatoes 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

8 wks before frost

Transplant Outside

3 wks after frost

Southern Delaware (Zones 7b)

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

Start Seeds Indoors

8 wks before frost

Transplant Outside

3 wks after frost

Growing Sweet Potatoes in Delaware

Sweet Potatoes in Delaware's Climate

Sweet potatoes are achievable in your climate with effort. Plant slips in late May to early June when soil reaches 65°F. Black plastic mulch is essential for warming soil. Choose 90-day varieties only. Harvest before first frost — this is critical because even light frost damages tubers. Your window is tight but workable.

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 sweet potatoes 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. Sweet Potatoes 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 sweet potatoes — transplant timing shifts by several weeks across the state.

Growing Tips

Grow from slips, not seeds. Start slips from a sweet potato in water 8 weeks before transplanting. Cure harvested tubers in warmth for 10 days.

Companion Planting

Plant sweet potatoes alongside these companions for better growth:

Beans Corn

Keep sweet potatoes away from:

Squash

The Bottom Line

Sweet Potatoes 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