Dover, DE planting zone & frost dates
Dover is in USDA hardiness zone 7b. The last spring frost usually comes around April 4 and the first fall frost around November 4, for a growing season of about 214 days.
Planting calendar for Dover
Dates are counted from the average last spring frost (April 4) 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 7 – Feb 21 Transplant outdoors: Apr 11 – Apr 18 |
| Peppers | Start seeds indoors: Jan 24 – Feb 7 Transplant outdoors: Apr 18 – Apr 25 |
| Eggplant | Start seeds indoors: Jan 24 – Feb 7 Transplant outdoors: Apr 18 – Apr 25 |
| Broccoli | Start seeds indoors: Jan 24 – Feb 7 Transplant outdoors: Mar 7 – Mar 21 |
| Cabbage | Start seeds indoors: Jan 24 – Feb 7 Transplant outdoors: Mar 7 – Mar 21 |
| Onions (sets) | Plant outdoors: Mar 7 – Mar 21 |
| Peas | Sow outdoors: Feb 21 – Mar 7 |
| Spinach | Sow outdoors: Feb 21 – Mar 7 |
| Lettuce | Sow outdoors: Mar 7 – Mar 21 |
| Carrots | Sow outdoors: Mar 7 – Mar 21 |
| Potatoes | Plant outdoors: Mar 7 – Mar 21 |
| Beans | Sow outdoors: Apr 11 – Apr 18 |
| Sweet corn | Sow outdoors: Apr 11 – Apr 18 |
| Cucumbers | Sow outdoors: Apr 11 – Apr 18 |
| Squash & zucchini | Sow outdoors: Apr 11 – Apr 18 |
| Basil | Start seeds indoors: Feb 21 – Mar 7 Transplant outdoors: Apr 11 – Apr 18 |
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).
Frost risk in detail
| 90% chance | 50% chance | 10% chance | |
|---|---|---|---|
| Last 32°F frost in spring is after | Mar 22 | Apr 4 | Apr 17 |
| First 32°F frost in fall is before | Nov 18 | Nov 4 | Oct 23 |
How to read it: in spring there is a 10% chance of a frost after April 17, so that is a safe date for tender plants. In fall there is a 10% chance of frost before October 23. A hard freeze (28°F) usually ends around March 25.
Hardiness zone by ZIP code in Dover
- 19901 zone 7b
- 19903 zone 7b
- 19904 zone 7b
- 19905 zone 7b
- 19906 zone 7b
Nearby cities
- Smyrna zone 7b, last frost Apr 4
- Milford zone 7b, last frost Apr 11
- Middletown zone 7b, last frost Apr 7
- Bear zone 7b, last frost Apr 7
- Glasgow zone 7b, last frost Apr 7
- Brookside zone 7b, last frost Apr 7
- Newark zone 7b, last frost Apr 7
- Wilmington zone 7b, last frost Apr 7
Questions
What growing zone is Dover, DE?
Dover 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 Dover?
The average last spring frost (32°F) in Dover is April 4. There is still a 10% chance of frost until April 17.
When can I plant tomatoes in Dover?
Transplant tomatoes outdoors 1–2 weeks after the average last frost: around Apr 11 – Apr 18. Start seeds indoors 6–8 weeks before the last frost.
Frost dates: NOAA U.S. Climate Normals 1991–2020, station Dover, DE (USC00072730), 2.1 km (1.3 mi) from the city center, elevation 9 m, based on 30 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.