Growing zones, or hardiness zones, refer to geographical regions, defined by climatic conditions, in which a specific variety of plants are capable of growing. These zones are determined by the USDA and consider conditions such as a plant’s ability to withstand minimal temperatures typical to that specific zone.
This tool is essential for gardeners to ensure successful growth of plants and vegetables in their area, based on the temperature range that the plants can tolerate. This information is important for selecting plants that are well-suited to the local climate and for ensuring that the plants will thrive in their environment.
These zones are divided into 10-degree Fahrenheit zones and range from 2-11 (or 12 if you include Hawaii). The higher the number associated with the zone, the warmer that zone is. The USDA sets the zones by basing each zone on the average annual extreme minimum temperature as recorded during a 30-year period in the past.
Different plants will perform differently depending on the zone they are planted in. For example, one grower’s perennial might be another grower’s annual, depending on conditions associated with a specific zone. These conditions have the ability to modify a plant’s capability to last for more than one season. Consider geraniums; in the mountains and/or high desert areas, these plants might be container plants or annuals, whereas in warmer regions like Florida, this plant might be perennial.
So, how can you determine your particular hardiness zone? Through the USDA, you can find a detailed, interactive map of the United States that breaks down each zone. When you find your location, click your zone and use the information provided to help plan the garden of your dreams!
You can access the interactive map here: https://planthardiness.ars.usda.gov/