Ohio Plant Hardiness Zones Map And Gardening Guide

Summary

Ohio plant hardiness zones include 5b, 6a, 6b and 7a. It has a wide range of temperatures depending on where you are in the state, but the overall average minimum extreme winter temperatures range from -15°F (-26.1°C) to 0°F (-17.8°C).

The climate range in Ohio includes a temperate climate and a continental climate. Both climates fluctuate in temperatures widely, although it is generally warmer in the temperate climate range. Both climates experience a wide range of weather.^1-8

Ohio has a short growing season. You could extend the season using a greenhouse, especially in the temperate climate ranges because of the slightly warmer growing conditions. It is beneficial to use native plants in this state, as they have adapted to the growing conditions.

Ohio has extreme weather, including harsh winters, flooding, and tornadoes. Consider planning for these forms of extreme weather to have better gardening success.^9-11

Plant suggestions include but are not limited to the following:^11-24

Flowering dogwood
Bottlebrush buckeye
Smooth Blue Aster
Sugar snaps peas
Greek Oregano
Spicebush
Highbush Blueberry
Wild stonecrop

Ohio 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)
5b	-15°F to -10°F -26.1°C to – 23.3°C	Early to mid-May	Late September to early October
6a	-10°F to -5°F -23.3°C to 20.6°C	Late April to early May	Early to mid-October
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

Frost Date Sources: 1-5

Ohio’s Growing Conditions

General Climate^1-8

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

Ohio’s climate has a wide range of weather patterns. Most of the state is temperate, including most of the southern area and a small portion bordering Lake Erie.

Temperate climates generally have a wide range of weather and fluctuating temperatures with four distinct seasons. These include warm to hot summers and cool to mild winters. The growing season in this climate is typically a bit milder than in the northern, continental part of the state, which means you can grow a wider variety of plants.

Ohio’s northern continental zone generally has a shorter growing season, with colder winters and warmer summers. This area will also experience four seasons but usually with more extreme temperatures ranging in all seasons.

Ohio generally experiences moderate precipitation consistently throughout the year.

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^9-11

Flooding

Ohio is located along the tornado belt, which means there are more extreme weather events. These can include severe thunderstorms, heavy rainfall, high winds, and even hail, all of which can result in flooding.

Flooding and waterlogging can cause lasting issues for your plants and garden, including root saturation, surface flooding, and water contamination. To ensure your garden thrives year after year, it’s important to develop mitigation techniques for these weather events. This could include specific garden designs that accommodate high fluctuations in water levels.

Tornadoes

Tornadoes are strong, violent winds that occur during severe thunderstorms. These storms can be extremely loud and have an eerie green hue that takes over the sky. They produce heavy rainfall, flash flooding, and hail. Tornadoes can be immensely destructive to your home and garden.

It’s important to watch the weather as meteorologists can predict when a storm will hit. Tornado season in Ohio typically occurs from mid-spring until mid-summer, when conditions lead to shifting weather patterns and drastic temperature changes.

Planning for extreme weather events such as tornadoes helps ensure that your garden survives season after season. For example, you could focus on native plants with strong root systems to combat high winds.

Extreme Cold

Ohio can experience extreme cold during the winter (particularly in the northern part of the state). This is a time for hibernation and rest in the garden, and you’ll typically have already cleaned up in the fall.

The extreme cold can do damage to a garden if you select incorrect plants for this climate. Picking the right plants for your hardiness zone ensures their success. Winter prep can also help to mitigate winter die-off. Winter die-off occurs when extreme cold kills plants. Focusing on native plants can help avoid this as they are acclimated to the weather in Ohio.

Growing Season

Ohio’s growing season is generally short to mid-length, extending from late April to mid-October (depending on your zone and region).

Using a cold frame or greenhouse can extend the length of your growing season. Due to the severe weather in the spring, it would be advantageous to focus on late summer-fall-blooming plants.

Ohio Gardening Tips

A grass path leading through a beautiful garden with trees and flowers.

Choose The Right Plants

Plant selection in Ohio is one of the best ways to mitigate damage during tornado season, although it also may just come down to sheer luck. Choosing plants with strong root systems helps keep them intact during heavy winds and flash flooding. Native plants are more resistant to the drastic weather changes in their particular hardiness zone and are, therefore, more likely to survive the extremes in their range.

Follow Proper Garden Design

Proper garden design can work wonders in areas with lots of flooding. Check out rain garden designs, where you dig trenches beneath or around your garden and fit them with piping and drainage rocks to help with the dissipation and directional flow of the water.

Raised garden boxes elevate your plants and increase drainage as well. This gardening method works best for annual veggies and more delicate plants as they are more sensitive to extreme weather conditions.

Additionally, putting your favorite plants in movable containers and bringing them inside during the severe weather is a good way to keep them alive.

Do Winter Garden Prep

With the right plant selection, you can manage extreme winters. Native plants are acclimated to Ohio weather systems and, therefore, can tolerate colder winters. Another way to help your plants manage the cold is to mulch your garden beds with leaf mulch. This keeps your plants’ roots warm and cozy under a layer of snow. You can also wrap mid-sized shrubs in burlap to create another barrier against the wind and cold.

Embrace A Zen-Like Detachment

Living in a state where tornadoes happen every spring, it’s important to know that as the seasons change, so will your garden. Try to remove any attachment to the garden and look at it as a growing experience!

The thought of losing plants and a garden that you worked so hard on can seem frustrating, but having this knowledge ahead of time can help you plan accordingly.

This might mean growing plants from seed as it is a more economical approach. Another option would be to start with a smaller garden and, as the seasons progress, see what does well and what doesn’t. This way, you can continue to build with resilient plants, creating a stronger, more durable garden.

If you have plants you love, keep them in pots and bring them inside during the more turbulent seasons. Although impermanence can be a hard notion to accept, it is a part of growing a garden and a wonderful lesson on life.

Stay strong, and keep planting!

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.

Ohio Plant Suggestions^11-24

Trees

Flowering dogwood (Cornus florida)
Eastern Redcedar (Juniperus virginiana)
American beech (Fagus grandifolia)

Shrubs

Rosebay rhododendron (R. maximum)
Bottlebrush buckeye (Aesculus parviflora)
Buttonbush (Cephalanthus occidentalis)

Flowers

Black-eyed Susan (Rudbeckia hirta)
Smooth Blue Aster (Symphyotrichum laeve)
Rose Milkweed (Asclepias incarnata)

Vegetables

Buttercrunch lettuce (Lactuca sativa var. capitata)
Sugar snaps peas (Pisum sativum var. macrocarpon ser.)
Winterbor Kale (rassica oleracea var. acephala)

Herbs

Greek Oregano (Origanum vulgare)
Lemon Thyme (Thymus citriodorus)
Apple Mint (Mentha suaveolens)

Spices

Garlic (Allium sativum)
Spicebush (lindera benzoin)
Ginger (Zingiber officinale)

Fruits

Gala Apple (Malus domestica)
Highbush Blueberry (V. corymbosum)
Smooth Blackberry (R. canadensis)

Succulents

Wild stonecrop (Sedum ternatum)
Hens & Chicks (Sempervivum tectorum)
Prickly Pear Cactus (Opuntia humifusa)

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

“USDA Plant Hardiness Zone Map”. US Department of Agriculture. Accessed March 11, 2024.
“Frost Dates for Columbus, OH”. Almanac. Accessed March 11, 2024.
“Frost Dates for Ashland, OH”. Almanac. Accessed March 11, 2024.
“Frost Dates for Cincinnati, OH”.Almanac. Accessed March 11, 2024.
“Frost Dates for Cleveland, OH”.Almanac. Accessed March 11, 2024.
“Köppen climate classification”. Wikipedia. March 9, 2024. Accessed March 11, 2024.
“Temperate climate”. Wikipedia. March 9, 2024. Accessed March 11, 2024.
“Continental climate”. Wikipedia. March 7, 2024. Accessed February 20, 2024.
“Tornado safety tips”. Ohio.Gov. February 18, 2022. Accessed March 11, 2024.
“Garden Flooding Tips”. Vodaland Canada. January 4, 2024. Accessed March 11, 2024
“Native Plants”. Ohio State University. Accessed March 11, 2024.
“Native Shrubs: Creating Living Landscapes for Birds, Butterflies, Bees, and Other Beneficials”. Ohio State University. Accessed March 11, 2024.
“Lettuce – Buttercrunch”. Bumble Seeds. Accessed March 11, 2024.
Shelton, Renee. “Sugar Snap Peas”.Cultivate to Plate. January 4, 2018. Accessed March 11, 2024
“Kale in the Brassicas Database”. Garden.org. March 8, 2014, Accessed on March 10, 2024.
“Greek Oregano (Origanum vulgare)”. Salt Spring Seeds. Accessed March 10, 2024
“Thymus x citriodorus (Lemon Thyme)” Gardenia.net. Accessed March 10, 2024.
“Mentha suaveolens (Apple Mint)”. Gardenia.net. Accessed March 10, 2024.
Mahr, Susan. “Garlic, Allium sativum”. Wisconsin Horticulture. Accessed March 10, 2024
Mahr, Susan. “Ginger, Zingiber officinale”.Wisconsin Horticulture. Accessed March 10, 2024
“Malus domestica ‘Gala’”. Perfect Garden. Accessed March 10, 2024
Grant, Bonnie L. “Hens And Chicks”. Gardening know how. March 11, 2021. Accessed March 10,2024
“Sedum ternatum (Wild Stonecrop)”. Gardenia.net. Accessed March 10, 2024.
“Eastern Prickly Pear Cactus”. Canada.gov. April 2010. Accessed on March 10, 2024.