Wilmington, OH planting zone & frost dates
Wilmington is in USDA hardiness zone 6b. The last spring frost usually comes around April 17 and the first fall frost around October 22, for a growing season of about 187 days.
Planting calendar for Wilmington
Dates are counted from the average last spring frost (April 17) 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 20 – Mar 6 Transplant outdoors: Apr 24 – May 1 |
| Peppers | Start seeds indoors: Feb 6 – Feb 20 Transplant outdoors: May 1 – May 8 |
| Eggplant | Start seeds indoors: Feb 6 – Feb 20 Transplant outdoors: May 1 – May 8 |
| Broccoli | Start seeds indoors: Feb 6 – Feb 20 Transplant outdoors: Mar 20 – Apr 3 |
| Cabbage | Start seeds indoors: Feb 6 – Feb 20 Transplant outdoors: Mar 20 – Apr 3 |
| Onions (sets) | Plant outdoors: Mar 20 – Apr 3 |
| Peas | Sow outdoors: Mar 6 – Mar 20 |
| Spinach | Sow outdoors: Mar 6 – Mar 20 |
| Lettuce | Sow outdoors: Mar 20 – Apr 3 |
| Carrots | Sow outdoors: Mar 20 – Apr 3 |
| Potatoes | Plant outdoors: Mar 20 – Apr 3 |
| Beans | Sow outdoors: Apr 24 – May 1 |
| Sweet corn | Sow outdoors: Apr 24 – May 1 |
| Cucumbers | Sow outdoors: Apr 24 – May 1 |
| Squash & zucchini | Sow outdoors: Apr 24 – May 1 |
| Basil | Start seeds indoors: Mar 6 – Mar 20 Transplant outdoors: Apr 24 – May 1 |
Fall garden: cool-season crops like lettuce, spinach and kale can be sown again around Aug 27 (8 weeks before the average first fall frost on Oct 22).
Useful for zone 6b 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
- Cold frame / mini greenhouse — adds weeks to a short season
As an Amazon Associate, FrostZoneMap earns from qualifying purchases, at no extra cost to you.
Frost risk in detail
| 90% chance | 50% chance | 10% chance | |
|---|---|---|---|
| Last 32°F frost in spring is after | Apr 3 | Apr 17 | May 4 |
| First 32°F frost in fall is before | Nov 3 | Oct 22 | Oct 9 |
How to read it: in spring there is a 10% chance of a frost after May 4, so that is a safe date for tender plants. In fall there is a 10% chance of frost before October 9. A hard freeze (28°F) usually ends around April 4.
Hardiness zone by ZIP code in Wilmington
- 45177 zone 6b
Nearby cities
- Xenia zone 6b, last frost Apr 18
- Beavercreek zone 6b, last frost Apr 18
- Lebanon zone 6b, last frost Apr 24
- Centerville zone 6b, last frost Apr 17
- Goshen zone 6b, last frost Apr 23
- Washington Court House zone 6b, last frost Apr 23
- Springboro zone 6b, last frost Apr 17
- Kettering zone 6b, last frost Apr 18
Questions
What growing zone is Wilmington, OH?
Wilmington is in USDA Plant Hardiness Zone 6b (average extreme winter low -5°F to 0°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 17. There is still a 10% chance of frost until May 4.
When can I plant tomatoes in Wilmington?
Transplant tomatoes outdoors 1–2 weeks after the average last frost: around Apr 24 – May 1. Start seeds indoors 6–8 weeks before the last frost.
Frost dates: NOAA U.S. Climate Normals 1991–2020, station Wfo Wilmington, OH (USC00339220), 2.7 km (1.7 mi) from the city center, elevation 321 m, based on 24 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.