In short, just about anything goes.
Nobody has to dictate terms to anyone else.
The most encouraging trend seems to be for Canadians to take ownership of their own gardens. Grow what you like. Gardening is one of the best possible ways to express yourself. Some people want orderly, well-manicured lawns and neat colourful but uniform borders. Others like huge bursts of colour or lots of variation in flowerbeds overflowing with a wide assortment of blooms.