This USDA Zone Map is provided for your convenience and should be used only as a general guide to what will survive your winter temperatures. There are other factors, like good drainage and normal winters, that affect a plant's survival over the winter. 

We have combined the sub zones on the official map into just 11 zones. So 1A and 1B have the same minimum rating on our list. 1 is the coldest and 11 is the warmest. Plants rated Zone 1 will survive the winter in all zones. Plants rated Zone 2 will die in zone 1, but will survive in Zones 2 through 11 and so on. To help you choose plants that are right for your winters, we have put together a Gardening by Zone list of all the plants in our catalog. 

If you need to find which zone you are in, you may use this tool.