Kentucky Growing Zones Explained

Kentucky Growing Zones Explained

Today, most people in Kentucky grow their food on over twelve million acres in operation recorded by 2020. It doesn’t matter if you are an experienced gardener or starting, as knowing which growing zones you live in is essential for your gardening success. 

Most of Kentucky falls under USDA growing zone 6, divided into two subzones – 6a and 6b. The remaining part of the state lies in zone 7a. This article will discuss various Kentucky’s growing zones and how they can affect your gardening activities.

What are Growing Zones or Plant Hardiness Zones?

Growing zones describe the geographic regions where you grow your plants. The United States Department of Agriculture – USDA – has established these zones, and gardeners and landscapers often use them to determine which plants will do best in particular areas. 

USDA hardiness zones describe the average annual minimum temperatures based on climate, altitude, and topography. These zones range from zone 1 to 13, as shown in the USDA plant hardiness zone map. Each area has a range of minimum temperatures expected for that zone. On average, each zone’s temperature is 10°F colder or hotter than the one next to it. Zone 1 is the coldest, while zone 13 is the hottest.

How to Know Your Growing Zone in Kentucky 

The United States Department of Agriculture (USDA) has a map to help you determine your hardiness zone. It’s interactive so that you can find your hardiness zone by zip code or state. You can search by your state in the search area, giving you all the growing zones in that particular state. If you need a more specific result, use your zip code which gives you precise details.

Kentucky’s Growing Zones

Kentucky is located in the upland South and stretches into Appalachia. The state has an excellent growing season in USDA hardiness zone 6, with two subzones – 6a and 6b. The average extreme minimum low temperature in this zone is -10°F to 0°F. However, a small part of the southwestern region is in Zone 7a with low minimum temperatures of 0 to 5°F.

USDA plant growing zones in Kentucky Minimum temperature(°Fahrenheit)
6a -10 to -5°F
6b   -5 to 0°F
7a   0 to 5°F

Kentucky’s Growing Zone 6a

Zone 6’s growing season is considered medium-long for most plants, vegetables, and flowers. Most seed companies provide this information on seed packets with your convenience in mind. Zone 6a has an average winter temperature of -10 to -5°F. 

However, temperatures don’t necessarily stay in this range since it can get much colder. October 17 to October 31 are the projected dates for first frost. The last frost dates occur from April 1 to April 21. These dates may fluctuate, leading to early or late frosts.

Which Plants Thrive in Kentucky’s Zone 6a?

Gardening in zone 6a is quite rewarding because many plants do well there. While some plants may need to be started indoors in March and April, it’s possible to transplant them outside in May or June. Doing this will give you a long, productive growing season. Here are some plants that do well in this zone.

Vegetables That Do Well in Kentucky’s Zone 6a and When to Plant Them

tomatoes

March is a great month for planting cold weather crops in this zone. These plants can be planted as early as March and include lettuces, radishes, and peas. Other types of vegetables that can be grown in this zone include the following.

  • Tomatoes
  • Carrots
  • Potatoes
  • Corn
  • Beans
  • Peppers
  • Cucumbers
  • Melons
  • Kale
  • Onions
  • Celery
  • Spinach
  • Broccoli
  • Radish
  • Peas
  • Brussels sprouts
  • Cabbage
  • Cauliflower
  • Eggplant

Best Perennials to Grow in Kentucky’s Zone 6a and When to Plant Them

Lupinus purple swirl

Zone 6a perennials can handle temperatures between -10 to -5 degrees Fahrenheit. Zone 6 perennials are planted somewhere between mid-March and mid-November. Growing different perennials will ensure your garden has a vibrant display of colors. Below is a list of some of the best perennials for your zone 6a garden.

  • Lupinus purple swirl
  • Bee balm
  • Monarda blue moon
  • Coneflower
  • Papaver Orientale Turkish delight
  • Aconitum napellus monkshood
  • Salvia
  • Ajuga reptans Bronze beauty
  • Daisy
  • Viola Sorbet Lemon Blueberry Swirl
  • Daylily
  • Coral bells
  • Echinacea Julia Coneflower
  • Hosta
  • Hellebore
  • Campanula Samantha
  • Achillea fanal
  • Iris Cloud Ballet
  • Dianthus Fire and Ice
  • Fritillaria Meleagris
  • Geum Triflorum
  • Anemone Wild Swan
  • Helianthus Happy Days

Best Annuals for your Kentucky’s Zone 6a Garden and When to Plant Them

Calibrachoa

Although annuals don’t grow for more than one season, zone 6a is a perfect place to plant them. The mild winters and long growing seasons in this zone offer the best conditions for growth. You can plant your annuals anytime from April 20 to May 20, after the last frost. Here’s a list of annuals you can grow in this zone.

  • Calibrachoa
  • Bacopa
  • Begonia
  • Cleome
  • Cockscomb
  • Cosmos
  • Four o’clock
  • Angelonia
  • Fuchsia
  • Geranium
  • Heliotrope
  • Impatiens
  • Lantana
  • Lobelia
  • Marigold
  • Mexican Heather

Farmers Tips for Growing in Kentucky’s Zone 6a

  • You can start sowing your cold-weather vegetables outside from March. They include peas, radishes, and lettuce.
  • For you to have a longer and more productive season, consider starting your seeds indoors from March and April and then transplant them outside in May or June.
  • Planting sun-loving perennials such as roses, peonies, irises, daylilies, hibiscus, and coneflowers is a great way to add beauty and color to your garden. These plants do best when getting about 6-8 hours of direct sunlight a day. Without enough sunlight, plants will bloom poorly or not at all.

Kentucky’s Growing Zone 6b

Zone 6b has average winter temperatures ranging from -5°F to 0°F. The last frost dates are from April 1 to mid-April, with the first frost coming in mid to late November. 

Plants That Thrive in Kentucky’s Zone 6b

Plenty of plants and flowers can be grown in zone 6b. Most of these plants and flowers are annuals that die with the frost. They usually come from warmer climates and can be treated as annuals in zones 6. Gardening in zones 6 is advantageous because so many plants do well there. Below is a list of plants to grow in your zone 6b garden.

Vegetables to Grow in Kentucky’s Zone 6b and When to Grow Them

broccoli

The best time to plant vegetables in zone 6b is from mid-March after the last frost, through mid-November. It’s important to remember that these are just guidelines. Winter or summer might come earlier or last longer than usual. You can also extend your spring or fall growing season by starting your seeds indoors. Here are some types of vegetables that will do well in your zone 6b garden.

  • Broccoli
  • Collards
  • Onions
  • Kale
  • Chard
  • Sugar peas
  • Lettuce
  • Pumpkins 
  • Spinach
  • Beets
  • Potatoes
  • Arugula
  • Zinnias
  • Tomatoes
  • Carrots
  • Peas
  • Peppers
  • Turnips
  • Summer squash
  • Melons
  • Eggplant
  • Corns
  • Dry beans
  • Pole beans

Best Perennials to Grow in Your Kentucky’s Zone 6 Garden and When to Plant Them

Joe pyweed

Flowers are classified either as perennials or annuals. Perennials come back each year – meaning that they do not die after one growing season like annuals. After the frost period has passed, perennials sprout again and may grow larger and produce bigger blooms with each passing year. 

This cycle continues until they reach full maturity. From mid-March to mid-September, you can plant perennials in your garden. Some of the best perennials for your zone 6b garden are listed below.

  • Joe pyweed
  • Catmint
  • Coneflowers
  • Black-eyed Susan
  • Creeping jenny
  • Daylilies
  • Salvia
  • Lambs Ears
  • Hostas
  • Coral bell
  • Japanese painted fern
  • Lenten roses
  • Bleeding hearts
  • Astilbe
  • Jack frost
  • Solomon’s seal

Best Annuals to Grow in Your Kentucky Garden and When to Plant Them

Annuals are flowering plants that go their entire life cycle in a single season, from seeds, growth, flowering, and eventually death. You can plant your annuals in zone 6b after the last frost, which starts around April 20 to May 20. Some of the annuals that will thrive in your garden include;

  • Cleome
  • Cockscomb 
  • Angelonia
  • Calibrachoa
  • Fuchsia
  • Marigold
  • Sweet Alyssum
  • Torenia 
  • Mexican Heather
  • Bacopa
  • Begonia
  • Moss Rose
  • Nasturtium
  • Geranium
  • Heliotrope
  • Impatiens
  • Cosmos
  • Four O’Clocks
  • Snapdragons
  • Strawflower
  • Sunflower
  • Lantana
  • Lobelia
  • Nemesia
  • Petunia

Farmers Tips for Growing in Kentucky’s Zone 6b

  • Starting your seeds indoors six to eight weeks before the last frost will give you better results and extend your growing season.
  • If you plan to grow any direct sow vegetables such as cabbage, beans, corn, or cucumber, you can start planting from the beginning of May.
  • Remember to check the maturation date on the seeds packet. Doing this will guide you on how long your crop will take to mature compared to the length of the growing season.

Kentucky’s Growing Zone 7a

If you are looking for a long growing season with plenty of opportunities to enjoy flowers, trees, shrubs, and vegetables, zone 7a is perfect for you. This zone has an average minimum temperature of 0 – 5 degrees Fahrenheit. Zone 7a’s first frost date is mid-October, with the last frost coming in mid-April. 

Plants That Thrive in Kentucky’s Zone 7a

If you live in zone 7a, that means you are in a moderate climate. The average growing season lasts about eight months, and the annual minimum temp is 0-5 degrees Fahrenheit. The first frost usually comes around November 15, and the last one occurs around April 15. Planting a garden in zone 7a is easy for you because many crops and ornamental plants can grow well in this area.

Vegetables to Grow in Kentuckys Zone 7a and When to Grow Them

The long growing season in this zone gives you plenty of options when growing your vegetables. When it comes to cool-weather vegetables, you can plant them in your garden in early February. These vegetables include; 

  • Beets
  • Broccoli
  • Carrots
  • Lettuce
  • Onion
  • Peas
  • Potatoes
  • Radishes
  • Spinach
  • Turnips
  • Kale
  • collards 

You can plant corn in March. In April, plant warm-season vegetables such as 

  • Okra
  • Eggplants
  • Beans
  • Peppers
  • Cucumbers
  • Squash
  • Tomatoes
  • Cauliflower
  • Kales

Best Perennials to Grow in Kentuckys Zone 7a and When to Plant Them

Daylily

Zone 7a’s climate favors perennials in a significant way. It enjoys mild winters and moderate summers compared to the freezing winters in the lower zones and scorching heat in the upper zones. With such an advantage, you can select a variety of perennials for your zone 7a garden with ease. You can sow your seeds indoors six to eight weeks before the last frost and then transplant them outside. Below is a list of perennials suitable for your zone 7a garden.

  • Daylily
  • Barrenwort
  • Russian sage
  • Tickseed
  • Hellebore
  • Sedum
  • Baptisia
  • Coneflower
  • Catmint
  • Asiatic lily
  • Hostas
  • Peony
  • Cranesbill
  • Garden flox
  • Blazing star
  • Oriental lily
  • Japanese anemone
  • Moss phlox
  • Culvers root
  • Sedum
  • Hollyhock
  • Butterfly weed

Best Annuals to Grow in Kentuckys Zone 7a Garden and When to Plant Them

Pansy

Many annuals can grow well in zone 7a, particularly because summers here aren’t punishing. Nearly any annual can be grown in this zone. Fall is a great time to plant many cool-season annuals, which bloom in the winter and spring. Alternatively, you can plant them in late winter or early spring for flowers in the spring.  Here are some of the most popular zone 7a annuals. 

  • Pansy
  • Ornamental kale 
  • Snapdragon
  • Dianthus
  • Begonia
  • Coleus
  • Pansy
  • Lobelia
  • Monkeyflower
  • Forget me not
  • Impatiens
  • Cosmos
  • Coreopsis
  • Lantana
  • Salvia
  • Spider flower
  • Strawflower
  • Globe amaranth
  • Marigold
  • Petunia
  • Portulaca
  • Geranium
  • Dahlia
  • Cypress vine

Farmers Tips for Growing in Kentucky’s Zone 7a

  • Plant after the last frost has passed. By doing this, you will get an extended growing season and establish the plants’ roots before the hot summer sun.
  • Use mulches on your garden to maintain moisture in the soil, suppress weeds, and moderate the soil temperature.
  • Your garden’s soil may become compact during the winter period. Tilling it in the spring will help you prepare it for a new planting season.

FAQs

Question: When Can I Plant Annual Flowers in Kentucky’s Zone 7a?

Answer: The life cycle of annuals is short. You can plant them as early as spring or even fall. For example, pansies and ornamental kale are hardy annuals, meaning they can withstand a light frost. Half-hardy zone 7a annual flowers, like dianthus or alyssum, can also stay alive throughout winter. Tender annuals, like zinnia and impatiens, might not fare that well.

Question: Which Tropical Plants Can I Grow in Kentucky’s Zone 6?

Answer: In a zone 6 climate, there are many great options. Rice paper plant, hardy eucalyptus, and yucca rostrata are just a few of them. The clumping or Mexican bamboos have been reported successful in cold regions and provide a tropical feel. Crape myrtle has been a favorite in zone 6 climates for a while now and thrive there.

Question: Can I Grow Cherry Trees in Kentucky’s Zone 7?

Answer: You can grow cherries in Kentucky’s zone 7. Cherry trees are self-sterile and thrive in a large garden or orchard. When planting them, make sure you plant at least two or three trees because they pollinate each other.

Question: When Can I Plant Tomatoes in Kentucky’s Zone 6?

The best thing to do is to start your tomatoes seedlings indoors. Six weeks ahead of the usual last-frost date is an excellent target for starting your favorite tomato plant. So in Zone 6, for example, you should be planting out in early April instead of mid-May.

Conclusion

Kentucky’s growing zones offer an excellent variety of climatic conditions for your gardening and backyard farming projects. If you love gardening, you will need to understand your USDA growing zones for Kentucky. These zones and weather patterns help you determine what type of plants and seeds will grow well with the right amount of sunlight, rainfall, and temperature.

With this guide, you also get an idea of the best time to plant in your area. Most of the state is in growing zone 6, except for the westernmost counties, which fall in zone 7a. Hopefully, now you have a better idea of the best times for gardening, planting vegetables, and other plants. 

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