Wilmington, DE planting zone & frost dates
Wilmington is in USDA hardiness zone 7b. The last spring frost usually comes around April 7 and the first fall frost around November 4, for a growing season of about 209 days.
Planting calendar for Wilmington
Dates are counted from the average last spring frost (April 7) using the typical timing recommended by U.S. extension services. Warm-season crops go out only after the danger of frost has passed and the soil has warmed.
| Crop | When |
|---|---|
| Tomatoes | Start seeds indoors: Feb 10 – Feb 24 Transplant outdoors: Apr 14 – Apr 21 |
| Peppers | Start seeds indoors: Jan 27 – Feb 10 Transplant outdoors: Apr 21 – Apr 28 |
| Eggplant | Start seeds indoors: Jan 27 – Feb 10 Transplant outdoors: Apr 21 – Apr 28 |
| Broccoli | Start seeds indoors: Jan 27 – Feb 10 Transplant outdoors: Mar 10 – Mar 24 |
| Cabbage | Start seeds indoors: Jan 27 – Feb 10 Transplant outdoors: Mar 10 – Mar 24 |
| Onions (sets) | Plant outdoors: Mar 10 – Mar 24 |
| Peas | Sow outdoors: Feb 24 – Mar 10 |
| Spinach | Sow outdoors: Feb 24 – Mar 10 |
| Lettuce | Sow outdoors: Mar 10 – Mar 24 |
| Carrots | Sow outdoors: Mar 10 – Mar 24 |
| Potatoes | Plant outdoors: Mar 10 – Mar 24 |
| Beans | Sow outdoors: Apr 14 – Apr 21 |
| Sweet corn | Sow outdoors: Apr 14 – Apr 21 |
| Cucumbers | Sow outdoors: Apr 14 – Apr 21 |
| Squash & zucchini | Sow outdoors: Apr 14 – Apr 21 |
| Basil | Start seeds indoors: Feb 24 – Mar 10 Transplant outdoors: Apr 14 – Apr 21 |
Fall garden: cool-season crops like lettuce, spinach and kale can be sown again around Sep 9 (8 weeks before the average first fall frost on Nov 4).
Useful for zone 7b gardens
- Seed starting kit with dome — to start seeds indoors before the last frost
- LED grow light for seedlings — stops leggy seedlings
- Frost cloth / plant covers — for late spring and early fall frosts
- Soil thermometer — warm-season crops need soil above 60°F
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Frost risk in detail
| 90% chance | 50% chance | 10% chance | |
|---|---|---|---|
| Last 32°F frost in spring is after | Mar 26 | Apr 7 | Apr 24 |
| First 32°F frost in fall is before | Nov 19 | Nov 4 | Oct 21 |
How to read it: in spring there is a 10% chance of a frost after April 24, so that is a safe date for tender plants. In fall there is a 10% chance of frost before October 21. A hard freeze (28°F) usually ends around March 29.
Hardiness zone by ZIP code in Wilmington
- 19801 zone 7b
- 19802 zone 7b
- 19803 zone 7b
- 19804 zone 7b
- 19805 zone 7b
- 19806 zone 7b
- 19807 zone 7b
- 19808 zone 7b
- 19809 zone 7b
- 19810 zone 7b
- 19850 zone 7b
- 19880 zone 7b
- 19884 zone 7b
- 19885 zone 7b
- 19886 zone 7b
- 19890 zone 7b
- 19891 zone 7b
- 19892 zone 7b
- 19893 zone 7b
- 19894 zone 7b
- 19895 zone 7b
- 19896 zone 7b
- 19897 zone 7b
- 19898 zone 7b
- 19899 zone 7b
Nearby cities
- Pike Creek Valley zone 7b, last frost Apr 7
- Hockessin zone 7a, last frost Apr 19
- Bear zone 7b, last frost Apr 7
- Brookside zone 7b, last frost Apr 7
- Newark zone 7b, last frost Apr 7
- Glasgow zone 7b, last frost Apr 7
- Middletown zone 7b, last frost Apr 7
- Smyrna zone 7b, last frost Apr 4
Questions
What growing zone is Wilmington, DE?
Wilmington is in USDA Plant Hardiness Zone 7b (average extreme winter low 5°F to 10°F), according to the USDA 2023 map.
When is the last frost in Wilmington?
The average last spring frost (32°F) in Wilmington is April 7. There is still a 10% chance of frost until April 24.
When can I plant tomatoes in Wilmington?
Transplant tomatoes outdoors 1–2 weeks after the average last frost: around Apr 14 – Apr 21. Start seeds indoors 6–8 weeks before the last frost.
Frost dates: NOAA U.S. Climate Normals 1991–2020, station Wilmington Porter Rsch, DE (USC00079605), 3.1 km (1.9 mi) from the city center, elevation 82 m, based on 29 years of records. Hardiness zone: USDA Plant Hardiness Zone Map 2023 for the ZIP code nearest to the city center. Microclimates (valleys, hills, cities, coasts) can be warmer or colder: check the local forecast before planting. How we calculate the data.