Ashtabula, OH planting zone & frost dates

Ashtabula is in USDA hardiness zone 6b. The last spring frost usually comes around May 2 and the first fall frost around October 21, for a growing season of about 171 days.

USDA hardiness zone6bavg. extreme winter low -5°F to 0°F
Average last spring frostMay 290% chance of no frost after May 20
Average first fall frostOctober 2110% chance of frost by October 4
Growing season171 daysfrost-free days in an average year

Planting calendar for Ashtabula

Dates are counted from the average last spring frost (May 2) 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.

CropWhen
TomatoesStart seeds indoors: Mar 7 – Mar 21
Transplant outdoors: May 9 – May 16
PeppersStart seeds indoors: Feb 21 – Mar 7
Transplant outdoors: May 16 – May 23
EggplantStart seeds indoors: Feb 21 – Mar 7
Transplant outdoors: May 16 – May 23
BroccoliStart seeds indoors: Feb 21 – Mar 7
Transplant outdoors: Apr 4 – Apr 18
CabbageStart seeds indoors: Feb 21 – Mar 7
Transplant outdoors: Apr 4 – Apr 18
Onions (sets)Plant outdoors: Apr 4 – Apr 18
PeasSow outdoors: Mar 21 – Apr 4
SpinachSow outdoors: Mar 21 – Apr 4
LettuceSow outdoors: Apr 4 – Apr 18
CarrotsSow outdoors: Apr 4 – Apr 18
PotatoesPlant outdoors: Apr 4 – Apr 18
BeansSow outdoors: May 9 – May 16
Sweet cornSow outdoors: May 9 – May 16
CucumbersSow outdoors: May 9 – May 16
Squash & zucchiniSow outdoors: May 9 – May 16
BasilStart seeds indoors: Mar 21 – Apr 4
Transplant outdoors: May 9 – May 16

Fall garden: cool-season crops like lettuce, spinach and kale can be sown again around Aug 26 (8 weeks before the average first fall frost on Oct 21).

Useful for zone 6b gardens

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Frost risk in detail

90% chance50% chance10% chance
Last 32°F frost in spring is afterApr 18May 2May 20
First 32°F frost in fall is beforeNov 5Oct 21Oct 4

How to read it: in spring there is a 10% chance of a frost after May 20, so that is a safe date for tender plants. In fall there is a 10% chance of frost before October 4. A hard freeze (28°F) usually ends around April 21.

Hardiness zone by ZIP code in Ashtabula

Nearby cities

All cities in Ohio → · Other zone 6b cities →

Questions

What growing zone is Ashtabula, OH?

Ashtabula 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 Ashtabula?

The average last spring frost (32°F) in Ashtabula is May 2. There is still a 10% chance of frost until May 20.

When can I plant tomatoes in Ashtabula?

Transplant tomatoes outdoors 1–2 weeks after the average last frost: around May 9 – May 16. Start seeds indoors 6–8 weeks before the last frost.

Frost dates: NOAA U.S. Climate Normals 1991–2020, station Ashtabula Co Ap, OH (USW00004857), 12.4 km (7.7 mi) from the city center, elevation 282 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.