When you’re out shopping for plants, you might come across labels that mention “Zones 3-7” or similar numbers. These references indicate the plant hardiness zones where specific plants will thrive.
Knowing your gardening zone is crucial in selecting plants that are well-suited to your region’s climate, ensuring that your garden thrives all year round. By understanding your zone, you can make informed choices that support the health and longevity of your outdoor plants.
What is a gardening zone?
A gardening zone, also known as a plant hardiness zone, is a defined geographic area that helps gardeners determine which plants are most likely to thrive in the local climate. The USDA categorizes these zones based on the average minimum temperatures of the area. The USDA Plant Hardiness Zone Map divides North America into 13 zones based on the average annual minimum winter temperature.
In response to the impact of climate change, the USDA released an updated hardiness zone map in 2023. The updated map showed a northward shift in the zones, reflecting the changing conditions.
Why do gardening zones matter?
Gardening zones provide essential information about your area’s climate, especially its coldest temperatures. By choosing plants suited to your zone, you reduce the risk of winter damage, ensuring better survival rates and lowering replacement costs.
Understanding your zone also helps in planning your planting schedule, including the best times for sowing and transplanting. Many gardening resources and nurseries offer tailored advice and products based on these zones, making it easier to find the right guidance and supplies.
What does heat zone mean?
Some plant labels also mention a heat zone. A heat zone is a geographic area defined by the American Horticultural Society (AHS) based on the average number of days per year that a region experiences temperatures over 86°F (30°C). These zones complement the USDA Plant Hardiness Zones, which are based on minimum cold temperatures.
The AHS Plant Heat Zone Map identifies 12 zones, indicating regions where plants are subjected to high temperatures that could affect their growth, survival, and flowering times. Understanding heat zones is essential for selecting plants that can tolerate local heat conditions, preventing issues like withering or sun scorching, especially during the hotter parts of the year. By considering both the hardiness zone and heat zone, you can choose plants that will thrive in your region.
Step-by-step guide to finding your gardening zone
Visit the USDA plant hardiness zone map:
The USDA plant hardiness zone map is a valuable resource for determining gardening zones in the United States. It provides detailed information about the temperature extremes of each zone.
Enter your zip code:
Enter your zip code to find out your exact gardening zone. This simple method eliminates the need to interpret the color-coded map on your own. Each hardiness zone differs by 10 degrees Fahrenheit and is often divided into subzones “a” and “b,” with a 5-degree Fahrenheit difference.
Understand the zone meanings:
Each zone corresponds to a specific range of minimum winter temperatures. For example, Zone 3 might experience temperatures as low as -40 to -30°F, while Zone 9 might only dip to 20-30°F. Knowing these ranges will help you choose plants that are appropriate for your area’s climate.
Consider zones when buying plants:
Nursery tags and seed packets often include zone information. To enhance the survival and growth of the plants you purchase, ensure they are suitable for your zone. Don’t forget to take your region’s heat zone into account when selecting plants.
Account for microclimates:
Keep in mind that microclimates within your garden, such as shaded areas or windy spots, can impact the suitability of certain plants, even within your zone.
How to select plants based on your gardening zones
When choosing plants for your garden, it’s important to consider both the USDA Plant Hardiness Zone and the AHS Heat Zone listed on the plant tag. Most plant tags and plant information on websites will indicate the hardiness zones, with many also listing the heat zone. By matching these zones with your local climate, you can determine if a plant is likely to thrive in your garden. For instance, if you reside in USDA Zone 8 and AHS Heat Zone 7, look for plants tagged within those zones to ensure they are well-suited to your region’s winter cold and summer heat.
