What is a zone??

Canada and the US are divided into USDA hardiness zones based on average annual minimal temperatures.  Calgary is officially Zone 3, so any perennial you see rated zone 3 or lower should be fully hardy here.  That said, Calgary is dry and windy, and chinooks are especially hard on our woodies and perennials.  Then again, some areas of Calgary are harsher than others due to elevation, lack of mature trees, etc.  It is also possible to have warmer microclimates in a sheltered spot in your yard, for example a south-facing foundation bed and furthermore, sometimes plant ratings aren't very accurate.  Karl Foerster feather reed grass is a trendy, vertical ornamental grass that you see everywhere but is officially rated zone 5.  Basically, check out what plants are doing well in your neighbourhood, go to a nursery with knowledgable staff, and feel to take a few risks.

Comments

[foobar]

This is not strictly correct. Canada also has its own zone system, and thusly Calgary is zone 3A. Gardeners need to be careful with this, as many plants are labelled with USDA zones, and their zones don't quite match up with ours.