Plant Hardiness Zones offer general guidance to the kinds of plants that will survive winter in a given area. The warmer the climate, the higher the number of the zone. Zones assume that all plants are receiving adequate water. The accuracy of zone coding can be substantially distorted by a lack of water. Zones are also affected by altitude, soil aeration, light, day length, air movement, surrounding structures, and soil pH.
Microclimates like English Bay in Vancouver can provide enough protection to grow palm trees. However, neighbours on a hilly street in North Vancouver may find themselves in different zones. Surprisingly, Vancouver shares its Zone 7 to 8 rating with northern Texas. Here is our Plant Zone Finder for Canada.
The figures below offer a general guide to determining Plant Hardiness Zones. Think of the minimum winter temperature in your area in a typical year.
Coldest Temperature in your local region = Your Zone
-45°C (-49°F) – Zone 1 -45 to -40°C (-49 to -40°F) – Zone 2 -40 to -35°C (-40 to -31°F) – Zone 3 -35 to -29°C (-31 to -20°F) – Zone 4 -29 to-23°C (-20 to -9°F) – Zone 5 -23 to -18°C (-9 to -1°F) – Zone 6 -18 to -12°C (-1 to 10°F) – Zone 7 -12 to -7°C (10 to 19°F) – Zone 8 -7 to -1°C (19 to 30°F) – Zone 9
Plant Hardiness Zones are not the same as Average Frost Dates. These two core gardening concepts are only related because they have to do with cold weather.