London, OH planting zone & frost dates
London is in USDA hardiness zone 6a. The last spring frost usually comes around April 24 and the first fall frost around October 18, for a growing season of about 175 days.
Planting calendar for London
Dates are counted from the average last spring frost (April 24) 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 27 – Mar 13 Transplant outdoors: May 1 – May 8 |
| Peppers | Start seeds indoors: Feb 13 – Feb 27 Transplant outdoors: May 8 – May 15 |
| Eggplant | Start seeds indoors: Feb 13 – Feb 27 Transplant outdoors: May 8 – May 15 |
| Broccoli | Start seeds indoors: Feb 13 – Feb 27 Transplant outdoors: Mar 27 – Apr 10 |
| Cabbage | Start seeds indoors: Feb 13 – Feb 27 Transplant outdoors: Mar 27 – Apr 10 |
| Onions (sets) | Plant outdoors: Mar 27 – Apr 10 |
| Peas | Sow outdoors: Mar 13 – Mar 27 |
| Spinach | Sow outdoors: Mar 13 – Mar 27 |
| Lettuce | Sow outdoors: Mar 27 – Apr 10 |
| Carrots | Sow outdoors: Mar 27 – Apr 10 |
| Potatoes | Plant outdoors: Mar 27 – Apr 10 |
| Beans | Sow outdoors: May 1 – May 8 |
| Sweet corn | Sow outdoors: May 1 – May 8 |
| Cucumbers | Sow outdoors: May 1 – May 8 |
| Squash & zucchini | Sow outdoors: May 1 – May 8 |
| Basil | Start seeds indoors: Mar 13 – Mar 27 Transplant outdoors: May 1 – May 8 |
Fall garden: cool-season crops like lettuce, spinach and kale can be sown again around Aug 23 (8 weeks before the average first fall frost on Oct 18).
Useful for zone 6a 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
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Frost risk in detail
| 90% chance | 50% chance | 10% chance | |
|---|---|---|---|
| Last 32°F frost in spring is after | Apr 10 | Apr 24 | May 10 |
| First 32°F frost in fall is before | Nov 1 | Oct 18 | Oct 5 |
How to read it: in spring there is a 10% chance of a frost after May 10, so that is a safe date for tender plants. In fall there is a 10% chance of frost before October 5. A hard freeze (28°F) usually ends around April 14.
Hardiness zone by ZIP code in London
- 43140 zone 6a
Nearby cities
- Hilliard zone 6b, last frost Apr 22
- Washington Court House zone 6b, last frost Apr 23
- Grove City zone 6b, last frost Apr 23
- Marysville zone 6b, last frost Apr 19
- Springfield zone 6a, last frost Apr 25
- Urbana zone 6a, last frost Apr 24
- Dublin zone 6b, last frost Apr 22
- Upper Arlington zone 6b, last frost Apr 20
Questions
What growing zone is London, OH?
London is in USDA Plant Hardiness Zone 6a (average extreme winter low -10°F to -5°F), according to the USDA 2023 map.
When is the last frost in London?
The average last spring frost (32°F) in London is April 24. There is still a 10% chance of frost until May 10.
When can I plant tomatoes in London?
Transplant tomatoes outdoors 1–2 weeks after the average last frost: around May 1 – May 8. Start seeds indoors 6–8 weeks before the last frost.
Frost dates: NOAA U.S. Climate Normals 1991–2020, station London Fish Hatchery, OH (USC00334681), 5.4 km (3.4 mi) from the city center, elevation 341 m, based on 22 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.