Cooperative Extensions - nationwide links to local contact informationWhile we can offer you general advice about hardiness related to your geographic location, it is always best to contact your local cooperative extension if you have questions involving planting in your specific environment or geographic area. They are generally well versed in what plants will work in your particular geographic location, and can generally offer accurate advice about when to plant and whether a plant is hardy, evergreen or annual in your area. If they cannot answer your question they may be able to refer you to local "master gardeners" who can. With so many variables to consider, this is the most accurate information available.
We strongly advise you to call them and confirm hardiness if you are in a "fringe" zone. For example, if a plant is described as hardy in zones 4-8, then zones 4 and 8 are fringe zones. Local conditions such as altitude, wind, excessive snowfall due to nearness to water, etc., may cause some parts of zone 4 to not be generally winter hardy for that plant. Similarly, local conditions in some parts of zone 8 may result in that plant requiring less sun than the rest of zone 8.
The Cooperative Extension System is a nationwide educational network. Each U.S. state has a state office at its land-grant university and a network of county or regional offices. These offices are staffed by one or more experts who provide useful, practical, and research-based information in communities of all sizes.
Most of the state websites contain links to contact information for regional or county offices. Select the office nearest to you.
Cold Hardiness Zones: Map, Zip Code Lookup
AHS Heat Zone Map