When to plant in Harrison, OH
USDA Zone 6bEverything below — frost dates, hardiness zone, and what to plant when in Harrison, Ohio — is derived from the closest NOAA station with complete climate normals.
Heads up: the nearest complete-normals station is about 15 km from Harrison, so your yard's frost dates can differ — a low spot or a paved city center can shift them by a week. Zone 6b means Harrison sees real winter cold, but a good range of perennials survive; the frost dates above govern when annual vegetables go out.
Frost probability
CHEVIOT 3 W · 1991–2020The date the last spring and first fall frost occur, by threshold and probability. A 90% date is later in spring — and earlier in fall — than a 10% date; the 50% · 32°F row is what most gardeners plan around. These are Harrison’s own odds, recorded at CHEVIOT 3 W.
| Threshold | SPRING 10% | SPRING 50% | SPRING 90% | FALL 10% | FALL 50% | FALL 90% |
|---|---|---|---|---|---|---|
| 36°F | May 14 | Apr 28 | Apr 13 | Oct 4 | Oct 17 | Oct 29 |
| 32°F | May 3 | Apr 16 | Apr 2 | Oct 14 | Oct 28 | Nov 9 |
| 28°F | Apr 21 | Apr 4 | Mar 20 | Oct 26 | Nov 7 | Nov 24 |
Download this table as CSV ↓ — every threshold and probability, plus this city’s planting-window dates.
What to plant now
TODAY · JULY 19Full-year planting calendar
Each bar is the exact window to take a planting action in Harrison, drawn to the day from the local frost dates. The dashed line is today.
Nearby weather stations
3 within 18 km · complete 32°F normalsWhen stations disagree by more than a few days, that spread is real microclimate variation — elevation, water, urban heat. Judge which station best matches your own yard.
Harrison planting FAQ
When is the last spring frost in Harrison, OH?
Harrison's average last spring frost falls near April 16 — the 50% mark at 32°F in the 1991–2020 normals. Hold tender transplants until the risk has passed, then plant out.
When is the first fall frost in Harrison, OH?
Expect Harrison's first fall frost near October 28 — a 50% chance of 32°F by that date. Bring in or cover tender crops ahead of it.
What hardiness zone is Harrison in?
Harrison is in USDA hardiness zone 6b. In zone 6b, winters are moderate — most common vegetables grow well in season.
How long is the growing season in Harrison?
There are roughly 195 frost-free days in Harrison (a moderate growing season), running from the average last frost around April 16 to the first fall frost near October 28.
When should I plant tomatoes in Harrison?
In Harrison, start tomato seeds indoors around February 19–March 5, then transplant seedlings outdoors around April 23 once the danger of frost has passed.
Never miss a window in Harrison
An email when it’s time to start seeds, transplant, and sow — timed to Harrison’s frost dates. Double opt-in, one-click unsubscribe, no spam.
Nearby cities
8 within reach- Dent · 13 km
- Mack · 15 km
- White Oak · 16 km
- Bridgetown · 17 km
- Francisville · 17 km
- Monfort Heights · 18 km
- Northbrook · 18 km
- Fairfield · 23 km
Frost dates recorded at CHEVIOT 3 W, 15 km from the city center · 1991–2020 NOAA climate normals · zone from the USDA/PRISM 2023 map. How we compute this.
BlissGarden. "When to Plant in Harrison, OH — Frost Dates & Zone 6b." Frost normals: NOAA NCEI U.S. Climate Normals 1991–2020, station USC00331516. Retrieved from https://blissgarden.com/ohio/harrison.