The USDA Hardiness Zone Map
Gardeners need a way to compare their garden climates with the climate where a plant is known to grow well. That’s why climate zone maps were created …
Zone maps are tools that show where various permanent landscape plants can adapt. If you want a shrub, perennial, or tree to survive and grow year after year, the plant must tolerate year-round conditions in your area, such as the lowest and highest temperatures and the amount and distribution of rainfall …
The USDA Hardiness Zone Map divides North America into 11 separate zones; each zone is 10°F warmer (or colder) in an average winter than the adjacent zone. Zone 1 is the coldest, as it encompasses extreme northern parts of Canada and the interior of Alaska. Zone 11 is the warmest, a tropical area found only in Hawaii, coastal Southern California and southernmost Florida …
We live in the Chicago area which is considered Zone 5 (light green on the map above). If you see a hardiness zone in a catalog or plant description tag, chances are it refers to the USDA map …
The average minimum temperature is not the only factor in figuring out whether a plant will survive in your garden. Soil types, rainfall, daytime temperatures, day length, wind, humidity and heat also play their roles.
Even within a city, a street, or a spot protected by a warm wall in your own garden, there may be microclimates that affect how plants grow …
So remember, zones are a good starting point to determine the best plants for your garden, but they are only a guide …
Click here for a handy tool to determine what zone you live in: Plant Hardiness Zone By Zip Code
