Kentucky Plant Hardiness Zones Map And Gardening Guide

Summary

Kentucky plant hardiness zones range from 6b to 7b. This state is in a humid subtropical climate zone, with a small area in the oceanic climate range. Kentucky experiences four seasons, with warm summers and moderately cold winters. Extreme weather in this state includes tornados, snow, and ice, and some areas will experience droughts.^1-11

Kentucky’s growing season is, on average, 170 days between the first and last frost. You can extend the growing season using cold frames, native plants, and by using a growing guide.^2-3

Kentucky has three different soil types within the state. Understanding the different types of soil will help aid in understanding what plants will do best and what other amendments you might need to add to the soil to create strong, healthy plants.¹²

Plant suggestions include but are not limited to the following:^13-22

Eastern Redbud
Wild Hydrangea
Virginia Bluebells
Peas
Common Rue
Mustard
Serviceberry
Gold Moss Stonecrop

Kentucky Plant Hardiness Zones

USDA Hardiness Zone	Average Minimum Extreme Winter Temperature Range Fahrenheit (°F) Celsius (°C)	Average Last Frost Date Range In Spring (Beginning Of The Growing Season)	Average First Frost Date Range In Autumn (End Of The Growing Season)
6b	-5°F to 0°F -20.6°C to 17.8°C	Late April to early May	Mid to late October
7a	0°F to 5°F -17.8°C to -15°C	Late April to early May	Mid to late October
7b	5°F to 10°F -15°C to -12.2°C	Early to mid-April	Late October to early November

Frost Date Sources: 1-2

Kentucky’s Growing Conditions

General Climate^1-4

Map showing Koppen climate types in Kentucky. — Credit to Wikipedia

The Kentucky climate is humid subtropical, with a very small portion of the south in a highland subtropical climate, a subcategory within the oceanic climate range.

Kentucky experiences all four seasons. It has warm summers and moderately cold winters, with the north portion of the state experiencing lows of -5°F (-20.6°C) with snow and ice. Humid subtropical climates typically don’t have a dry season and see rainfall year-round.

Highland subtropical climates exist at higher elevations within the subtropics. Kentucky experiences this climate due to the effects of the Appalachian mountain range. This climate experiences both cooler summers and winters, with less variation in temperature. This climate is also known to be dryer, with less precipitation annually.

Kentucky is known for its Kentucky bluegrass, a cool-season grass that is a popular option for lawns. In the spring, these bluegrass fields are full and fresh, welcoming spring with its crisp, bright blue hues.

Microclimates

USDA plant hardiness zones are an important starting point for your garden, but you’ll also need to consider microclimates.

Microclimates are areas where specific conditions create a climate different from the climate they’re situated in.

Buildings, fences, paved areas, or short hills and valleys can create these microclimates.

They can be as small as a space in your backyard or as large as a city.

In other words, learn about your local conditions from local experts to see if your garden falls into a microclimate.

Extreme Weather^5-11

Winter Weather

Kentucky experiences annual winters that can bring blizzards, ice, and sleet. Different areas of Kentucky can experience variations in winter weather, with the southwest receiving less snow compared to the eastern portions.

Cold frames and cold-hardy crops are a great way to beat the cold and extend your growing season. Lots of plants and veggies like parsley, kale, and salad greens can tolerate cold with some extra protection.

Droughts

In areas of the state that receive less precipitation annually, like in the highland subtropical regions, droughts can occur during the summer months. This can have a negative impact on your garden if you do not plant accordingly.

Planting drought-tolerant species can be more resilient to heat waves and overall are less work to maintain. Planting a native wildflower meadow is a great way to create an impactful garden that beats the heat. These gardens are also very beneficial to pollinator species.

Tornadoes

Kentucky can experience tornadoes in the spring and summer. These extreme weather events bring heavy winds, hail, and unpredictable weather. There are ways to prep your garden for tornados, but know that if a tornado reaches 115 mph winds or faster, it can uproot and destroy trees, no matter how prepared you are!

The overall health of your trees and shrubs, along with the plant’s age and structure, can be an indicator of how well it will endure an extreme weather event like a tornado. Check tips below for more information on how to prep your garden for tornado season.

Growing Season^2-3

Kentucky’s growing season lasts approximately 170 days on average. Typically, most crops need a minimum of 90 days to grow, making Kentucky’s growing season shorter to mid-length. Areas in zone 7 will be slightly longer due to its warmer weather.

Choose plants that are quick-growing, and follow a planting calendar. This will help you make the most out of your growing season.

Kentucky Gardening Tips^8-12

An old window box garden with flowers outside a home.

Pruning Trees And Shrubs For Tornado Season

Pruning your trees and shrubs before tornado season is an advantageous way to help ensure these plants thrive. Removing any dead, sickly wood and broken branches can help mitigate against broken, uprooted trees and downed limbs.

By thinning your trees, you reduce resistance to wind and create less turbulence within the canopy. Pruning also helps keep your home and garden safe by reducing the amount of fallen branches that could damage your property.

Heat-Tolerant And Low-Maintenance Plants

Using low-maintenance plants that are tolerant to heat is an easy and impactful way to grow your garden.

Native wildflower meadows are not only resilient to heat, but they can also be resilient to cold winters, making them the perfect solution for four-season gardening. These plants are typically direct sown in the fall, making them an economical approach to gardening as well.

Knowing Your Soil Type

Kentucky has three different soil types that are unique to the state. Knowing your soil type helps you choose the right plants for your area, and is great baseline data to help amend your soil to continue building healthy happy plants! All soil in Kentucky has excellent drainage, consisting of mostly fine gravel, loam, and silt. The three types of soil consistencies are called Baxter, Crider, and Maury series.

Consult With Local Professionals

Consulting with local gardening professionals allows you to benefit from their experience with your area’s conditions, the plants that do well there, and overall best practices.

Kentucky Plant Suggestions^13-22

Trees

Eastern Redbud (Cercis canadensis)
River Birch (Betula nigra)
Red Maple (Acer rubrum)

Shrubs

Wild Hydrangea (Hydrangea arborescens)
Carolina Rose (Rosa carolina)
New Jersey Tea (Ceanothus americanus)

Flowers

Virginia Bluebells (Mertensia virginica)
Wild Bergamot (Monarda fistulosa)
Purple Coneflower (Echinacea purpurea)

Vegetables

Corn (Zea mays)
Peas (Pisum sativum)
Radish (Raphanus sativus)

Herbs

Rosemary (Rosmarinus officinalis)
Common Rue, Herb-of-Grace (Ruta graveolens)
Wooly Thyme (Thymus praecox)

Spices

Garlic (Allium sativum)
Mustard (mustum ardens)
Dill (Anethum graveolens)

Fruits

Serviceberry (Amelanchier canadensis)
Black Walnut (Juglans nigra)
American Plum (Prunus americana)

Succulents

Woodland Stonecrop (Sedum ternatum)
Hen and Chicks (Sempervivum tectorum)
Goldmoss Stonecrop (Sedum acre)

Disclaimer

Any of the above can change and is not exhaustive.

Treat anything above like a good starter guide. Then use that as a foundation as you consult with local gardeners, professionals, forecasts, guides, and organizations.

Sources

“2023 USDA Kentucky Hardiness Zone Map“. US Department of Agriculture. Accessed April 14, 2024.
“Kentucky Vegetable Planting Calendar.” Urban Farmer. Accessed April 15, 2024.
“Growing and Harvesting in Kentucky.” Urban Farmer. Accessed April 15, 2024.
“Kentucky”. Wikipedia. April 13, 2024. Accessed April 14, 2024.
“Weather”. Kentucky Tourism. Accessed April 15, 2024.
“Koppen Climate Classification”. Weather STEM. Accessed April 15, 2024.
“Severe Weather”. Weather STEM. Accessed April 15, 2024.
“Winter Weather”. Weather STEM. Accessed April 15, 2024.
“Tornadoes”. Weather STEM. Accessed April 15, 2024.
“Droughts”. Weather STEM. Accessed April 15, 2024.
“Protect Your Home by Prepping Trees for Tornadoes and Hurricanes”. Davey. Accessed April 15, 2024.
“Growing and Harvesting in Kentucky”. Urban Farmer. 2018. Accessed April 15, 2024.
Gnadinger, Zac. “21 Kentucky Native Plants for Landscaping”. Kentucky Native Plants Project. July 11, 2023. Accessed April 15, 2024.
“Pisum sativum”. Missouri Botanical Gardens. Accessed April 15, 2024.
“Raphanus”. Wikipedia. October 26, 2023. Accessed April 15, 2024.
“KY Garden Flowers – Ranunculus to Ruta”. University of Kentucky. Accessed April 15, 2024.
“KY Garden Flowers – Tagetes to Tulipa”. University of Kentucky. Accessed April 15, 2024.
“Spice blend for homemade mustard”. Terre Exotique. Accessed April 15, 2024.
“Dill”. Wikipedia. April 14, 2024. Accessed April 15, 2024.
“Kentucky native fruit & nut producing trees”. Oakland Farm Trees. Accessed April 15, 2024.
“KY Garden Flowers – Sedum to Sutera”. University of Kentucky. Accessed April 15, 2024.
Shaw, J., D. Estes, B. Ruhfel, A.B. Morris, and T.R. Littlefield. “Tennessee-kentucky.plantatlas”. University of Tennessee at Chattanooga. September 28, 2023. Accessed April 15, 2024.