The USDA has recently released an updated Hardiness Zone Map. You may find that the zone for your area has changed. The hardiness zones for plants listed in our library and in our catalog, however, remain the same.
Go to http://planthardiness.ars.usda.gov/PHZMWeb/ to find additional maps and to search by zip code.
Zone ratings serve as a general guide for selecting a plant suitable for your area and indicate the minimum temperature we believe the variety will tolerate. Wind exposure, high temperature extremes, rapid temperature fluctuations, first and last frost dates, sun intensity, salt spray, soil drainage, and other factors also combine to determine your location’s “micro-climate”. Even though low temperature tolerance is generally accepted as the prime determinant of performance, these other factors must be taken into account in choosing the appropriate plant for your needs. We estimate each variety’s winter hardiness based upon our experience in this region. For each edition of our catalog we update some of our ratings in response to performance trials results from people in other areas. We welcome your comments and suggestions.