Sunday, April 26, 2009

Why Zones Don't Matter

I was in Creston yesterday and an interesting observation came from the audience. A lady in Kimberly  noted that Annabelle Hydrangeas (Zone 4-5) were so suited to their zone 3 climate that they had gone wild and reseeded all over. 

Compare that to zone 3 Calgary where Annabelle Hydrangeas only grow if you hold your mouth right and live in a sheltered or inner city location. In other words zones are not that important in the big picture or at least our maps are far too vague to be of any real use. What is important is snow cover in winter, soils, moisture and elevation all in combination. Obviously in Kimberly where the snow falls deep and stays - making the skiing there delightful - zones are not really that important as indicators to what will grow there. 

As usual an old gardening axiom - "Zones are important" - has nothing at all to do with achieving success in your garden. This is not the first time zones have been wrong - especially in a climate not actually measured very accurately by anyone. I am thinking of Mary in her zone 2a garden in Beaverlodge Alberta. Clearly she didn't know Hydrangeas were not zone 2 plants and she is quite happily growing them. Moral of the story: Have a look at zones but don't get too hung up on them! Consider soils and soil type, winter conditions and quantity of protective snow as well as elevation which will be an indicator of summer temperatures in the evening. Calgary has little snow in the winter, a high elevation (3,000 - 4,000 feet) and cold evenings in the summer - meanwhile hard winds dry out the soil in both winter and summer. In other words it isn't really a zone 3 or anything like it. They just don't measure zones  carefully enough to use them to predict much of anything. 

If you are new to gardening tour other gardens in your area and make a note of what grows. Then try to grow plants of similar type as you expand your palette. Join a garden club and see what the members of that club are growing and work from there. When it comes to zones you just have to fur-ged-a-bod-it.

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