The U.S. Department of Agriculture Plant Hardiness Zone Map divides North America into 11 zones. Each zone is 10 degrees warmer or cooler than its adjacent zones. Zones 6 to 10 cover the Southeastern United States. Zones are determined by average lowest winter temperatures and indicate which plants can survive the winter. In addition to the zone you live in, other factors to consider when choosing a plant include amount of sun and irrigation, soil type, summer temperatures and frost-free days.
A portion of Tennessee is located in Zone 6B, which has low temperatures of zero to minus 5 degrees Fahrenheit. This zone is good for cold-weather plants. Some warm-weather plants can survive the winter if there is adequate snow cover or other protection.
The interior of Mississippi, North Carolina, South Carolina, Georgia and Alabama are in Zone 7. Part of Tennessee is also located in Zone 7, which has low temperatures of zero to 10 F. A moderate to high amount of rainfall falls on this area, but little snow cover. Some warm-weather plants might need extra protection to survive the winter.
The coastlines of Mississippi, North Carolina, South Carolina, Georgia and Alabama are located in Zone 8. The interior of north Florida is also in Zone 8, where the low temperatures are 10 to 15 F. This zone has a short chill period in the winter, and hot, humid days in the summer.
Zones 9 and 10
The Florida peninsula is located in zones 9 and 10. Zone 9 has low temperatures of 20 to 30 F, while Zone 10 has low temperatures of 30 to 40 F. These zones have long growing seasons of hot, humid weather. Plants that need a chill period will not grow in zones 9 and 10 because the winters are too mild.