The USDA divides the United States, including Puerto Rico, into 13 regions, or Plant Hardiness Zones.
These zones are defined by an area’s average low temperature and are separated by a difference of 10 degrees Fahrenheit. Zone 1 is the coldest region with an average low temperature of -60 degrees Fahrenheit and zone 13 is the warmest region with an average low temperature of +60 degrees Fahrenheit. These zones can be further divided into “a” and “b” with a difference of 5 degrees Fahrenheit.
The USDA Hardiness Zones are divided according to average low temperatures since they represent the minimum temperatures a plant variety can withstand to survive. This means that it is most hardy in temperatures that do not drop below 0 degrees Fahrenheit.
Though the USDA Hardiness Zones provide reasonable guidelines when selecting plants for your area, it’s good to remember that they are only guidelines – there are always exceptions and other factors to consider if you really want to grow a plant variety just outside your zone.
Most likely a plant that is hardy in zone 8 – 10 will not survive a zone 6 winter since there is a 20 degree average low difference, but you may find success growing a zone 8 – 10 plant in zone 7 or a zone 7 plant in zone 6.
If you’re growing a plant variety in a slightly colder region than recommended (or even if your region is experiencing colder than usual temperatures) plan to use extra winter protection by adjusting the watering schedule, spreading additional mulch, and covering the plant with breathable material. See "Encore Azalea Cold Hardiness" and “4 Essential Winter Care Tips for Encore Azaleas” for more information.
You can also grow plants in containers and bring them indoors for winter. Test it out by planting one of our Encore Azaleas varieties in a container and bringing it indoors for winter. Place the container near a light source, e.g., a window or lamp, but make sure it doesn’t get chilly! Once spring comes, take your Encore Azalea container back outside and watch it thrive. See "Seven Steps to a Successful Encore Azalea Container Garden" for more information.
Encore Azalea is the best azalea you'll ever plant. Encore Azaleas are the world's best-selling re-blooming azalea with rich, colorful blooms in spring, summer and fall. Encore Azaleas have 31 varieties of bloom colors and sizes to choose from and thrive equally well in high filtered shade or sunny locations - unlike any other azalea in the world. Find a retailer near you.