The USDA has divided North America into 11 Hardiness Zones based on average annual minimum temperatures. The hardiness recommendations in our catalogue refer to these Zones and are based on information that current research indicates. They are offered without guarantee that a plant will grow in a particular zone. Occasionally we indicate an “extra” zone in parentheses. This means that the plant is marginal but may survive in that extra zone if afforded particularly good conditions. Remember that plants do not usually achieve their full hardiness for a season or two.

If you’re not sure which zone you’re in, follow this link to the current USDA Hardiness Zone Map: http://www.usna.usda.gov/Hardzone/ushzmap.html