What Planting Zones Are in Kentucky?
Kentucky spans USDA hardiness zones 6b to 7b, where the average coldest winter night ranges from −5 °F to 10 °F (−20.6 °C to −12.2 °C). Zone 7a covers the most ZIP codes, 78%, and zones 6b to 7a together cover 98% of the state.
Bars show each zone's share of the 933 Kentucky ZIP codes in the official 2023 USDA ZIP code table; select a zone for its temperatures and hardy plants.
What Hardiness Zone Are Kentucky Cities In?
Louisville is in zone 7a, Lexington is in zone 7a, Bowling Green is in zone 7a and Owensboro is in zone 7a. The table lists the zone, winter low and average frost dates for 18 Kentucky cities, using the ZIP code nearest each city center.
| City | ZIP | Zone | Winter low | Last frost | First frost |
|---|---|---|---|---|---|
| Louisville | 40218 | 7a | 0 °F to 5 °F | Apr 3 | Nov 3 |
| Lexington | 40505 | 7a | 0 °F to 5 °F | Apr 13 | Oct 28 |
| Bowling Green | 42101 | 7a | 0 °F to 5 °F | Apr 5 | Oct 31 |
| Owensboro | 42303 | 7a | 0 °F to 5 °F | Apr 2 | Nov 1 |
| Covington | 41014 | 6b | −5 °F to 0 °F | Apr 16 | Oct 25 |
| Georgetown | 40324 | 6b | −5 °F to 0 °F | Apr 13 | Oct 28 |
| Richmond | 40475 | 7a | 0 °F to 5 °F | Apr 15 | Oct 22 |
| Elizabethtown | 42701 | 7a | 0 °F to 5 °F | Apr 16 | Oct 25 |
| Florence | 41042 | 6b | −5 °F to 0 °F | Apr 18 | Oct 25 |
| Nicholasville | 40356 | 7a | 0 °F to 5 °F | Apr 7 | Nov 1 |
| Hopkinsville | 42240 | 7a | 0 °F to 5 °F | Apr 4 | Nov 2 |
| Frankfort | 40601 | 6b | −5 °F to 0 °F | Apr 15 | Oct 24 |
| Henderson | 42420 | 7a | 0 °F to 5 °F | Apr 9 | Oct 26 |
| Paducah | 42001 | 7a | 0 °F to 5 °F | Apr 5 | Oct 28 |
| Ashland | 41101 | 7a | 0 °F to 5 °F | Apr 22 | Oct 23 |
| Madisonville | 42431 | 7a | 0 °F to 5 °F | Apr 2 | Nov 1 |
| Murray | 42071 | 7b | 5 °F to 10 °F | Apr 5 | Nov 1 |
| Shelbyville | 40065 | 6b | −5 °F to 0 °F | May 1 | Oct 10 |
Zone: 2023 USDA ZIP code table for the ZIP code nearest each city's Census center point. Frost dates: 50% (median) dates from the nearest NOAA station, 1991–2020 normals. Cities: the largest Kentucky places by 2024 Census population estimates, spread across the state, plus the largest place in each common zone. Large cities can span two half zones.
Which Parts of Kentucky Are in Each Zone?
Zone 6b, the coldest Kentucky zone, covers 20% of ZIP codes around Covington, Georgetown and Florence. Zone 7b, the warmest, covers 2% around Murray, Mayfield and Hickman. The table lists the largest places in every zone.
| Zone | Avg. coldest night | Share of ZIPs | Largest places in this zone |
|---|---|---|---|
| Zone 6b | −5 °F to 0 °F | 20% (187) | Covington, Georgetown, Florence, Independence |
| Zone 7a | 0 °F to 5 °F | 78% (728) | Louisville, Lexington, Bowling Green, Owensboro |
| Zone 7b | 5 °F to 10 °F | 2% (18) | Murray, Mayfield, Hickman, Fulton |
Places: incorporated places with 1,000+ residents, assigned the zone of the ZIP code nearest their Census center point.
What Do the Hardiness Zones Mean for Kentucky Gardeners?
A Kentucky gardener in zone 7b sees winter lows about 10 °F milder than one in zone 6b, so a shrub or perennial that thrives in one part of the state can die in another. Choose plants rated to your own ZIP code's zone or colder.
Hardiness zones follow latitude, elevation and large bodies of water rather than state lines. Higher ground and inland valleys that trap cold air usually sit in colder half zones, while cities, coasts and large lakes moderate winter lows. Within Kentucky, a plant labelled “zones 6–7” survives winter in at least 98% of ZIP codes, but plants at the edge of their range benefit from mulch and a sheltered spot. Enter a ZIP code in the USDA hardiness zone finder by ZIP code to check your exact half zone before buying perennials.
A zone describes winter cold only. Summer heat, humidity, rainfall and soil decide whether a cold-hardy plant thrives, and planting dates for vegetables follow frost dates, not zones: two Kentucky towns in the same zone can have last frosts weeks apart.
What Plants Grow Well Across Kentucky?
221 plants in PlantoScan's catalogue are hardy in every zone from 6b to 7a, the zones that cover 98% of Kentucky ZIP codes. Popular examples include hydrangea, peony and daisy.
Hydrangea
Hydrangea macrophylla
Zone 5 – 9
AI generated
Peony
Paeonia lactiflora
Zone 3 – 8
AI generated
- DaisyBellis perennisPlantoScan
Daisy
Bellis perennis
Zone 4a – 8b
Chrysanthemum
Chrysanthemum morifolium
Zone 5a – 9b
PlantoscanAI generated
Poppy
Papaver somniferum
Zone 3a – 9b
AI generated
Carnation
Dianthus caryophyllus
Zone 5a – 9b
AI generated
Daffodil
Narcissus poeticus
Zone 3 – 8
AI generated
Azalea
Azalea indica
Zone 6a – 9b
AI generated
Arugula
Eruca sativa
Zone 5a – 10b
AI generated
Hardiness ranges come from PlantoScan's plant database; gardeners in Kentucky's colder or warmer edge zones should check each plant's full range.
When Is the Last Frost in Kentucky?
Across most Kentucky ZIP codes, the average last spring frost falls between April 3 and April 24, from April 2 in Owensboro to May 1 in Shelbyville. Tender vegetables such as tomatoes go out 1 to 2 weeks after the local date.
The last and first frost dates for Kentucky cities include the safer 90% planting date, the fall frost date, growing season length and a tomato planting table for each city.
Frequently Asked Questions
- What planting zone is Kentucky?
- Kentucky spans USDA hardiness zones 6b to 7b on the 2023 USDA Plant Hardiness Zone Map. Zone 7a is the most common, covering 78% of the state's 933 ZIP codes, and zones 6b to 7a together cover 98%.
- What hardiness zone is Louisville, Kentucky?
- Louisville is in USDA hardiness zone 7a (ZIP 40218), where the average coldest winter night reaches 0 °F to 5 °F. Its average last spring frost is April 3 and its first fall frost November 3.
- What hardiness zone is Lexington, Kentucky?
- Lexington is in USDA hardiness zone 7a (ZIP 40505), where the average coldest winter night reaches 0 °F to 5 °F. Its average last spring frost is April 13 and its first fall frost October 28.
- What hardiness zone is Bowling Green, Kentucky?
- Bowling Green is in USDA hardiness zone 7a (ZIP 42101), where the average coldest winter night reaches 0 °F to 5 °F. Its average last spring frost is April 5 and its first fall frost October 31.
- What is the coldest hardiness zone in Kentucky?
- Zone 6b (−5 °F to 0 °F) is the coldest zone in Kentucky, found in 187 ZIP codes around Covington and Georgetown. The warmest is zone 7b (5 °F to 10 °F), around Murray and Mayfield.
Zones: 2023 USDA Plant Hardiness Zone Map ZIP code table, USDA Agricultural Research Service and the PRISM Climate Group, Oregon State University, used without changes. Frost dates: NOAA National Centers for Environmental Information, 1991–2020 U.S. Climate Normals. City locations and populations: U.S. Census Bureau Gazetteer files and Vintage 2024 population estimates. PlantoScan is not affiliated with or endorsed by these agencies.