Canadian hardiness Zones are determined through minimum temperature ranges. Any exposed corner or protected nook of your gardenwill have it’s own unique microclimactic conditions, but generally speaking, the Lower Mainland of British Columbia is considered a Zone 7b (Abbotsford) to 9a (English Bay).  Minimum temperature ratings for Canadian hardiness Zone 7 is -12 to -17 degrees Celsius. An addition of ‘a’ denotes a slightly cooler range of minimum temperatures & an addition of  ‘b’ denotes a slightly warmer range of minimum temperatures. Obviously this is only a general system of categorization & plants are adaptive, flexible, & not constrained by our rules.