Hardiness zone maps help to determine what plants will grow (survive) where. Obviously not ALL plants will grow in ALL regions. Certainly these maps are excellent guides, but always keep in mind that there can be certain instances where there might be an exception. For example, you may live within zone 5, but an extremely warm wall in your yard may be a great place for a plant that requires zone 6 or 7 to survive.

The Canadian map and the US map differ slightly so it wouldn't hurt to be familiar with both as some plants/seeds/bulbs may have been imported and the zone requirements listed on the packaging will be of that of the country they come from.

There are a multitude of wonderful information sources on the internet that explain all the technical aspects of the hardiness zone maps. Below are the links to both the Canadian Plant Hardiness Zone Map as well as the United States Plant Hardiness Zone Map.