What the Hail: Coping with Calgary’s Climate

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Have you just moved to Calgary? Been a long-time resident? Below are five important things to know about successful gardening with our unique and sometimes crazy weather!

  1. Know Your Microclimate. Calgary’s elevation ranges from 975m up to 1295m. For example, the NW quadrant is the coolest but the first to get warm Chinook winds. The SE quadrant is warmest with moderating effects of the river and a lower elevation. Landscape contouring, windbreaks, and plant selection are important in all areas of the city.
  2. What is a Chinook? Described by the First Nations peoples as Tsniuks or ‘snow eaters’, these warm winter winds begin over the Pacific Ocean as warm air masses. The air cools as it rises, forming an arched cloud of precipitation on the west side of the mountains. The east or ‘lee side’ experiences warm winds as a result.

  1. Climate Extremes. We get it all in Calgary, sometimes all in one day! From minus 20-degree Celsius winter mornings warming to +5 degree Celsius in one day, often breaking dormancy of trees. Thunderstorms suddenly appear often bringing bouts of hail, instantly shredding many broad-leaved plants. Drought periods in summer desiccate plants and vegetables if not supplemented with irrigation. We can also get snow in spring, summer, and fall, wreaking havoc on trees, shrubs, and our tall perennials.
  2. Know Your Zones! Calgary is now considered zone 4a, upgraded from zone 3. Semi arid conditions have prevailed over the years allowing more flexibility in plant selection. We typically have an average of 117 frost free days, beginning May 21 with the first frost around September 16. Day length and ‘heat units’ for growing is short as well. Use of cold frames and purchasing larger plant material is a must to get lush!
  3. Plant Selection. Choose plants whose labels show zone 4a to zone 2. These will be the hardiest, giving you the most success. Consider higher zoned plants a fun experiment, but don’t expect some to overwinter without extra protection. Seek out native trees, shrubs, and perennials that are proven hardy in the Calgary area.

Beautiful gardens abound throughout the city even with all the weather extremes Calgary experiences. With the help of agencies like the Calgary Horticultural Society, you can have one too!