How to Find Your Canadian Plant Hardiness Zone

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Your plant hardiness zone is an important piece of information to guide your garden decisions. Here in Canada we have a wide range of garden zones with variations in each province. Have a look at the map and find the number for your area for growing plants, trees, shrubs, and vines, including annuals and perennials.

If you want to compare to USDA plant hardiness maps there is more information here.

Canadian Plant Hardiness Zones

Are Canadian and American Garden Zones the Same?

One common question is whether the Canadian and USDA plant hardiness zone systems are comparable, and the answer is, sort of.

While the USDA system is based on minimum temperatures, the most recent Canadian system includes minimum temperatures as well as rainfall, frost-free days, and other variables. When comparing standards and assigned zones, the difference is, perhaps, a half zone or so apart (e.g. 6a versus 6b). So, they’re close.

The purpose of these zones for home gardeners is help guide our plant selections. Zone is often the first consideration—can this perennial survive year-round in my climate?—and other growing conditions like sun, soil, and water come next.

Our zones range from 0 to 9, where zero is the coldest and 9 is the warmest average conditions.

For example, many clematis vines are suitable for zones 4 to 9. This means they will likely not survive winters below zone 4 temperatures or climates zone 10 or higher, but there are always exceptions to be found.

Some of the plants and seeds we purchase here in Canada may also be using the USDA zone system numbers, so keep in mind that it’s not precise, just a guideline.

Garden Zones Change Over Time

We also have to consider that our climate is always shifting, and zones will change over time, and the zone maps are not frequently updated.

Plus, every area has its own micro-climates.

A wide-open garden in zone 5 may be subject to extreme wind and freezes while a zone 5 garden enclosed with walls or other windbreaks may be a warmer micro-climate that never reaches the same lows.

There is no data available to the map makers to account for these exceptions, but you as a gardener will gradually learn how plants fare in your garden.

So, know your zone, but consider your circumstances as well.