Hardiness Zones
What are hardiness zones?
Hardiness zones are based on average annual minimum (winter) temperatures and define the geographical range in which a given plant might be expected to survive. Descriptions of plants in catalogues and garden stores use hardiness zone ratings to express a plant's tolerance for cold temperatures.
The zone map in use today has 11 zones and includes the continental U.S., Canada, Alaska, Hawaii and Mexico. The divisions between zones are based on differences of 10 degrees Fahrenheit and the 11 zones are subdivided into A and B categories that indicate differences of five degrees Fahrenheit.
Generally speaking, the lower the zone number, the colder the average annual minimum temperature. Conversely, the higher the zone number, the warmer the average annual minimum temperature. For example, Victoria, BC is considered a zone 8b, whereas Prince Albert, SK is a zone 1b.
It is important to note that all other factors affecting a plant's performance such as moisture, sun/shade and soil fertility have no bearing on the zone ratings of plants.
For a more detailed map of your area click on the map above or one of the following: