Ironton, OH planting zone & frost dates
Ironton is in USDA hardiness zone 7a. The last spring frost usually comes around April 22 and the first fall frost around October 23, for a growing season of about 181 days.
Planting calendar for Ironton
Dates are counted from the average last spring frost (April 22) 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 25 – Mar 11 Transplant outdoors: Apr 29 – May 6 |
| Peppers | Start seeds indoors: Feb 11 – Feb 25 Transplant outdoors: May 6 – May 13 |
| Eggplant | Start seeds indoors: Feb 11 – Feb 25 Transplant outdoors: May 6 – May 13 |
| Broccoli | Start seeds indoors: Feb 11 – Feb 25 Transplant outdoors: Mar 25 – Apr 8 |
| Cabbage | Start seeds indoors: Feb 11 – Feb 25 Transplant outdoors: Mar 25 – Apr 8 |
| Onions (sets) | Plant outdoors: Mar 25 – Apr 8 |
| Peas | Sow outdoors: Mar 11 – Mar 25 |
| Spinach | Sow outdoors: Mar 11 – Mar 25 |
| Lettuce | Sow outdoors: Mar 25 – Apr 8 |
| Carrots | Sow outdoors: Mar 25 – Apr 8 |
| Potatoes | Plant outdoors: Mar 25 – Apr 8 |
| Beans | Sow outdoors: Apr 29 – May 6 |
| Sweet corn | Sow outdoors: Apr 29 – May 6 |
| Cucumbers | Sow outdoors: Apr 29 – May 6 |
| Squash & zucchini | Sow outdoors: Apr 29 – May 6 |
| Basil | Start seeds indoors: Mar 11 – Mar 25 Transplant outdoors: Apr 29 – May 6 |
Fall garden: cool-season crops like lettuce, spinach and kale can be sown again around Aug 28 (8 weeks before the average first fall frost on Oct 23).
Useful for zone 7a 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 | Apr 6 | Apr 22 | May 11 |
| First 32°F frost in fall is before | Nov 3 | Oct 23 | Oct 11 |
How to read it: in spring there is a 10% chance of a frost after May 11, so that is a safe date for tender plants. In fall there is a 10% chance of frost before October 11. A hard freeze (28°F) usually ends around April 8.
Hardiness zone by ZIP code in Ironton
- 45638 zone 7a
Nearby cities
- Portsmouth zone 7a, last frost Apr 17
- Chillicothe zone 6b, last frost Apr 20
- Athens zone 6b, last frost Apr 25
- Circleville zone 6b, last frost Apr 17
- Lancaster zone 6a, last frost Apr 22
- Washington Court House zone 6b, last frost Apr 23
- Pickerington zone 6b, last frost Apr 23
- Grove City zone 6b, last frost Apr 23
Questions
What growing zone is Ironton, OH?
Ironton is in USDA Plant Hardiness Zone 7a (average extreme winter low 0°F to 5°F), according to the USDA 2023 map.
When is the last frost in Ironton?
The average last spring frost (32°F) in Ironton is April 22. There is still a 10% chance of frost until May 11.
When can I plant tomatoes in Ironton?
Transplant tomatoes outdoors 1–2 weeks after the average last frost: around Apr 29 – May 6. Start seeds indoors 6–8 weeks before the last frost.
Frost dates: NOAA U.S. Climate Normals 1991–2020, station Ashland, KY (USC00150254), 11.1 km (6.9 mi) from the city center, elevation 171 m, based on 23 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.