Landscape Design in Calgary’s Climate

Although Calgary has extremely cold winters, it is not as cold as Edmonton, which is located farther north; it’s amazing the difference 300km can make. The climate in Calgary can be difficult to categorize. The deep southeast of the city can be considered continental (cold winters and warm summers) while the north west part of the city is much colder. What can be a warm sunny barbecue type day for Mackenzie Lake could very well be a rainstorm or snowy day in Royal Oak or Rocky Ridge.

Calgary has sunny weather most of the year, even during winter, and most of its little rainfall falls during summer (except for Stampede time when it rains endlessly – but that’s another story). If you want your landscape to look interesting during Calgary’s dry winters, plant a section with different shapes and textures. While Calgary technically is classified as a having a 4a Plant Hardiness Zone, looking at the map below from Natural Resources Canada, you can see the NW of Calgary above the Bow River as being in the 3b Plant Hardiness Zone (think of those late September sunny barbeque days in Mahogany versus snow in the NW).

Calgary plant hardiness zones canada

Calgary plant hardiness zones. Click to enlarge.

The zones themselves give a good approximation of what can be grown, other factors such as soil quality and maintenance also play large roles.

Strategies for landscape design in dry climates

Windbreaks

A building must be protected from northern winter winds in very cold climate regions. To protect buildings from cold winter winds, dense windbreaks are used. Overheating in summer can be prevented by shading windows and walls facing south and west.

Facades

In very cold climate regions, the north façade is useful for partly raised land application. The north, east, and west should be planted with evergreen shrubs and trees with low branches. Grass and low shrubs should be applied to the southern windbreaker. Deciduous trees should be planted away from the building in southeast and southwest directions.

The southern side of the building could be designed with a sunken terrace with a light-colored reflective material to further capture and reflect the low winter sun. In addition, darker paving materials may also be used to promote snowmelt and capture warmth.

Creating a dead air space

Planting dense rows of evergreen trees and shrubs on the north and northwest sides of the building will help break the speed of the cold winter winds and create a snow trap. Dense evergreen shrubs located adjacent to the northern sides of the building can also create dead air spaces, providing insulation both during the winter and summer months.

Sheltering the Earth

For Calgary’s cold winters, earth sheltering may also be an effective solution. Using an elevational earth sheltering design can be effective if the building site is situated on a sunny south-facing slope.

What plants you can choose

Having deciduous shrubs and trees on the south side of a building can provide some summer shading when needed while letting in some winter sunlight.  On the east and west sides of a building, deciduous trees that provide a high canopy will provide warm winter rays but provide shade during the summer, and promote summer breezes.

Species that grow in a continental climate like in Calgary are truly countless, so it is difficult to distinguish which plants grow there. Among some examples are the American cranberry bush (Viburnum trilobum, USDA plant hardiness zones 2 to 7), which bears white flowers. In addition, several plants turn into berries in the cooler months, like wintergreen (Gaultheria procumbens, zones 3 through 7), as well as iris (Iris germanica, zones 3 through 10). Beautiful, upright petals and drooping sepals often come in vibrant yellows, purples, or blues.

With red, orange, and yellow petals, Gaillardia (Gaillardia Aristata, zones 4 to 8) is a stunning and easily cultivated perennial. Plants can take over a garden bed within a short period, which makes them a favorite of gardeners. In continental climates, hydrangeas grow well. With its large, flowering leaves, oakleaf hydrangeas (Hydrangea quercifolia, Zones 3 to 8) are a popular choice.

Planting tips for dry climates

  • Larger plants have shallow roots and cannot adapt, so the smaller the plant the better. The bigger the plant, the more dependent it is on water.
  • It is imperative that you cultivate deeply and break up the hardpan when you dig a planting hole to encourage deep rooting.
  • Adding organic matter to the soil, such as manure, will help it retain water and release it when the plants need it. A large amount of manure, however, especially if not distributed well, can create damp pockets that can kill plants with more delicate roots.
  • Using beneficial microbes, often available as root dips facilitate root growth by allowing plants to access nutrients and therefore establish more rapidly.
  • Little but frequent watering encourages shallow root growth. Summer is a dormant time for plants in dry climates, so they don’t grow or require much watering during the summer. Be sure to note your specific plant type and its watering needs and then consider the past weeks precipitation and temperature and what the plant might need in the coming weeks.
  • Gravel reduces water evaporation from the surface of the soil. Irrigation pipes can also be hidden and held down with gravel.

 

 

 

 

 

Leave a Reply