USDA hardiness zones — 2023 map
Kentucky hardiness zones — USDA planting zone map + what to grow
Zones 6a-7b · most of Kentucky is zone 6b · Southeast region
KentuckyUSDA zone range & map
On the 2023 USDA Plant Hardiness Zone Map, Kentucky spans zones 6a-7b. The map shades the state from the eastern Appalachian highlands (zone 6a) through to the Ohio River valley around Louisville (zone 7b). The single most common half-zone across the populated state is zone 6b — that is the figure to use if you only remember one number for Kentucky. Kentucky has a mild four-season climate with a long, humid summer and a winter that rarely tests hardy perennials.
| USDA zone range | Zones 6a-7b |
|---|---|
| Most common zone | Zone 6b |
| Coldest area | the eastern Appalachian highlands (zone 6a) |
| Warmest area | the Ohio River valley around Louisville (zone 7b) |
| Average last spring frost | mid-April |
| Average first fall frost | mid-October |
Source: USDA 2023 Plant Hardiness Zone Map (1991-2020 normals). Frost averages: NOAA/NCEI 1991-2020 climate normals. Local ZIP-level zones and frost dates can differ from these statewide figures.
Kentucky hardiness zones by major city
Zones shift across Kentucky with elevation and distance from the coast. Here is the 2023 USDA half-zone for the largest cities:
| City | USDA zone |
|---|---|
| Louisville | Zone 7a |
| Lexington | Zone 6b |
| Bowling Green | Zone 7a |
| Covington | Zone 6b |
Need your exact zone? Run the ZIP-code zone finder for a precise half-zone and frost dates for your address.
ZIP-code zones in Kentucky
Statewide ranges hide a lot. Tap your area for its exact USDA half-zone, last and first frost dates, and what to plant now:
- Louisville 40202 — Zone 7a
- Louisville (South) 40214 — Zone 7a
- Louisville (Okolona) 40219 — Zone 7a
- Louisville (Jeffersontown) 40299 — Zone 6b
- Lexington (West) 40504 — Zone 6b
- Lexington 40507 — Zone 6b
- Lexington (Downtown) 40508 — Zone 7a
- Frankfort 40601 — Zone 6b
- Covington 41011 — Zone 6b
- Florence 41042 — Zone 6b
- Bowling Green 42101 — Zone 7a
- Owensboro 42301 — Zone 7a
What Kentucky's zone range means for planting
Your hardiness zone tells you which perennials, shrubs, and trees will survive a typical Kentucky winter, and it anchors when tender crops can go outside. Because Kentucky spans 6a-7b, two gardeners in the same state can have very different planting calendars.
- Pick perennials hardy to your local zone. Across most of Kentucky that means at least zone 6b; gardeners in the eastern Appalachian highlands (zone 6a) should choose hardier plants.
- Anchor tender crops to your frost dates. With a last spring frost around mid-April and first fall frost around mid-October, set out tomatoes, peppers, and basil after the last frost and protect them before the first.
- Adjust for your microclimate. Urban heat, a south-facing slope, or a cold valley pocket can shift your effective zone and frost dates by a half-zone or more from the statewide figure.
Find your exact zone in Kentucky
The 6a-7b range is statewide. Growli pins your hardiness zone and frost dates to your exact ZIP code and sends a push notification before any forecast frost night for your saved location.
Frequently asked questions
What hardiness zone is Kentucky?
Kentucky spans USDA hardiness zones 6a-7b on the 2023 USDA Plant Hardiness Zone Map. The most common zone — covering the largest share of the populated state — is zone 6b. The coldest areas are the eastern Appalachian highlands (zone 6a) and the warmest are the Ohio River valley around Louisville (zone 7b).
When is the last frost in Kentucky?
Across most of Kentucky the average last spring frost falls around mid-April and the first fall frost around mid-October. These are statewide averages — colder, higher areas run later in spring and earlier in fall, so check a ZIP-level estimate for your exact spot.
What grows well in Kentucky?
Kentucky has a mild four-season climate with a long, humid summer and a winter that rarely tests hardy perennials. Match plants to your local half-zone within the 6a-7b range: choose varieties hardy to at least zone 6b for reliable overwintering, and time tender crops around your local frost dates. The zone 6 planting guide lists vegetables, fruit, and ornamentals suited to most of the state.
Why does Kentucky have more than one hardiness zone?
Hardiness zones track the average annual coldest temperature, which changes with latitude, elevation, distance from water, and urban heat. That is why Kentucky ranges from the eastern Appalachian highlands (zone 6a) to the Ohio River valley around Louisville (zone 7b) — a span of 6a-7b — even though it is a single state.
Did Kentucky's hardiness zone change in 2023?
The USDA updated the Plant Hardiness Zone Map in November 2023 using 1991-2020 climate data. About half the country, including parts of Kentucky, shifted to the next warmer half-zone versus the 2012 map. The 6a-7b range here reflects the current 2023 map. Always confirm your address against the official USDA map for plant-survival decisions.