A plant hardiness zone is a shorthand for "what can survive a typical winter here." Canada uses zones 0 (Arctic) through 8 (mild Pacific coast). The higher the number, the milder the climate and the broader the range of plants you can grow.
How to use your zone
When a plant tag says "hardy to Zone 4," it should survive winters in Zone 4 and warmer (5, 6, 7, 8). In a colder zone it will likely die back or need heavy protection. Match the plant's rating to your zone or lower for reliable perennials.
Zones aren't the whole story
- Microclimates matter: a south wall, a sheltered courtyard or a snowy spot can be a half-zone warmer.
- Season length (frost-free days) is just as important as winter low for vegetables.
- Snow cover dramatically improves survival, even in low zones.
Set your city on the homepage to see your exact zone, frost dates and a colour-coded zone spectrum.