Hello, I have been told Edmonton is zone 3 but some claim it is zone 4. I have been told by many that sugar maples can not grow or survive in Edmonton despite the fact I had one for 10 years at my old property and there are a few around the city. Today, I bought a acer rubrum (Armstrong) whose tag said zone 4 as well as an acer Saccharum fall fiesta which also said zone 4. My question is this.... What zone are these truly as when I look on the internet half say zone 3 and the other half say zone 4. Also, what zone is Edmonton as some say 3 including the Canadian government and some say 4???????? I also hear some trees get their zone rating from the USA who are slightly different then Canada. Ie, their zone 4 is our zone 3??? Anyhow, there are sugar maples and zone 4 trees in Edmonton but I have bought zone 4's which have croaked and some that have lived including my previous sugar maple which lived. I did buy another variety of maple which was a zone 4 And it died...... What are my chances with my acer rubrum and my acer Saccharum and what can I do to help them through the winter?
The zone rating is the same for the US and for Canada. According to the Agriculture and Agree-food Canada Edmonton is in zone 3. There can be, however, small sheltered pockets with zone 4 there.
They might survive for many years, but when a severe zone 3 winter occurred they would perish. Even if it is a once in twenty years, or even once in fifty years event, it would be enough to prevent that species from surviving long term in your zone. If you live in the city there may be local micro-climates due to heat from buildings that bump you up a zone.
So what zone is acer rubrum and sugar maples as half of the internet calls them Zone 3 and the other half calls them zone 4? How do I know the official answer? Thanks
There's very little difference in the effect of winter cold between zones 3 and 4. The main difference is that zone 3, being further north, has longer winters and shorter, slightly cooler summers. So any failure of any of these maples in Edmonton is more likely to be related to damage caused by an unusually short and/or cold summer not allowing the trees to complete their normal summer growth cycle.
The official answer as to hardiness, according to "Maples of the World" (as official as it gets): Sugar Maple (Acer sacccharum ssp saccharum): Zone III. Red Maple (Acer rubrum): Zone III (oddly this is not given in MOW but in the companion volume "Maples for Gardens") Individuals will vary in hardiness, along with Michael's explanation, it's kind of tough to make a general call between cold and colder... ;)
