USDA Plant Hardiness Zones
Educator Resources
No matter what time of year it is, it is extremely important to understand your plant hardiness zone if you are gardening or landscaping.
Before you get started, take a moment to review the USDA Plant Hardiness Zone Map for your area. Knowing your hardiness zone will help you pick the plants that are appropriate for where you live. The hardiness zone is most important for perennials and shrubs that will live through the winter.
Picking plants that are appropriate for your zone will aid in your gardening success and prevent frustrations. No one wants to see their hard work and money go to waste when they realize their plants didn’t make it through the winter.
Know your zone, so you can reap the benefits of seeing those plants grow and come up again and again, year after year!
USDA Plant Hardiness Zone Map
You have probably seen this color-coded map before and may have wondered, what does it all mean?
The 2023 USDA Plant Hardiness Zone Map is the standard by which gardeners and growers can determine which plants are most likely to thrive at a location. (planthardiness.ars.usda.gov)
The Hardiness Zone Map Explained
The Hardiness Zone Map will show the average annual extreme minimum temperature by location. Average annual extreme minimum temperature ranges are represented by different colors. The different colors are called zones and have an accompanying number. The color key on the map represents these minimum extreme temperatures and their zone number (for example, 35-40 degrees is zone 10b).
To show an example of how this works, we will use the states of West Virginia and Virginia.
According to the West Virginia map, this state experiences the extreme minimum temperatures of -20 to -15 and 0 to 5 depending on the location within the state. What this tells us is there are areas of West Virginia that get much colder in the winter months than other areas. Plants will need to be hardier to withstand the low temperatures of West Virginia zone 5a and 5b than in the state’s warmer zone 7a.
According to the Virginia map, this state experiences the extreme minimum temperatures of -20 to -15 and 10 to 15 depending on the location within the state. Virginia experiences a wider range of minimum temperatures. Plants that have the hardiness zone appropriate for Virginia Beach may not survive the winter months in the cooler mountain areas west of Charlottesville.
Find your Zone
To learn what zone you live in, visit the USDA Agricultural Research Service website. You can search for your hardiness zone by entering your ZIP Code. Once you enter the ZIP Code, it will give the exact zone for that location.
Another way to find your zone is to use the interactive map, which allows you to click on your state. Once you click on your state, you will be shown the color-coded map. Find your area, then use the map key to find your zone number.
Check for Plant Hardiness
You know your zone, so how do you find appropriate plants?
When choosing plants, make sure to refer to the tag. The tag will show the hardiness temperature along with other important information. Some plant tags will have the actual zone number (for example, 5a). Some tags will show the ‘hardy to’ temperature. Pick plants that are hardy to your zone, so they are more likely to live through your location’s winter months.
Make sure to pay attention to the additional information on the tag. Along with plant hardiness, you will need to understand the other conditions necessary for that plant’s success. If you are still unsure if the plant will work in a specific area in your yard, ask the gardening center sales associate for assistance.
Gardening can be rewarding and, at times, frustrating. Get in the zone and know your location’s USDA plant hardiness zone number to improve your gardening success. Planting plants appropriate for where you live can reward you with ongoing growth and beauty.
If you are interested in learning more about plants that work in your area, contact your local county extension office. Local extensions may have volunteer Master Gardeners who are trained to assist you.