Alberta has it's own climate...and Calgary it's unique too.
What time of year is best to prune?
When it comes to planting and pruning trees here, you have to be mindful of a couple of things. One... Is it a tree or a shrub? and why are you pruning it? Trees are woody, perennial plants that have one central stem, are generally more than 12 feet in height, and normally have a distinct head. Shrubs are woody, perennial plants that have a number of stems usually produced from near the soil line of the plant.
In Calgary, plants behave differently in seasons with the exception of evergreens. Plants that are active during spring and become dormant when winter comes. The ideal time to prune those trees would then be within that period of dormancy. Why? Because the plant, as the name suggest, is dormant; shutting down to ‘rejuvenate in the spring’. After the leaves have fallen are signs that the tree is dormant and will not undergo any stress when pruning.
Pruning is important because it enables rejuvenation of plants and aids in weeding out affected, unwanted and unproductive parts, thus increasing the potentiality of the plant. Evergreens can be pruned at any time of the year,
For flowering shrubs, try pruning them during early spring and avoid pruning them in the fall. This way, you won't make them exposed to winter frost conditions as their wounds wouldn’t have recuperated or hardened by then.
In Calgary, mid-fall has been the perfect time to trim perennial trees such as birch and maple simply because they reproduce during winter, among other reasons. Spruce, junipers, crabapple and popular trees are also well suited for pruning during winter. So why should you clip and trim your trees and shrubs during mid-fall towards winter?
- Fungal diseases, infections and pests are usually dormant making it easy for their eradication.
- The plant will face no stress and sap loss will be curbed.
- At this point, plants are not budding so no new life will be lost when trimming
- The structure of the plant is visible enough after leaves have fallen thus making it easy to identify what can be cut off and what can’t.
- When pruning at this period, few branches will be left, enabling the roots to reserve more food and energy for new growth and life in the coming season.
What trees are good to plant for Calgary?
Calgary is a unique growing climate, with weather conditions and challenges specific to our area. These tree species as examples of trees that grow well in Calgary’s variable weather.
Some deciduous trees listed below are larger trees but we have also listed some ornamental trees that are smaller and decorative. Remember to plan for your space. Some trees grow faster that you think and others grow wider that expected.
• Green Ash Fast growing tree. Size at maturity: 18m tall, 12m spread. Note- An extremely hardy tree; will grow in clay soil and survive extreme climates.
• Trembling Ash Fast growing tree. Size at maturity: 15m tall, 9m spread. Note - All when leaves turn brilliant gold. Needs pruning and removal of any suckers.
• Mayday Medium - Fast growing tree. Size at maturity: 6m tall, 8m spread. Note -First to leaf out in spring, with big creamy white flowers but is prone to Black Knot Fungus.
Planting a new the right way.
Your choice of tree or shrub will depend on two main things, the size of the area that you wish to fill, and the reason you are filling that spot. When considering a plant for a certain area, be sure to consider the plant's ultimate size. Be sure not to plant too close to houses, garages, or other permanent structures. Trees and shrubs can be planted anytime from spring to fall. If the ground can be worked you can plant.
Tree and Shrub Planting Steps
- Dig a hole 2 times the width of the root-ball or the pot that the plant comes in and a little deeper
- Remove the plant from its pot or remove burlap if bare root and gently massage roots
- Plant the tree or shrub in the hole at the same level it was planted in the pot
- Fill in hole with a mixture of topsoil and compost
- Water plant in well and fertilize with a transplant fertilizer (10-52-10) or Myke
Adding trees, adds benefits
Trees are critical to preserving and protecting the natural environment. They improve air quality, help retain storm water, provide homes and food for a variety of wildlife, helps to control temperatures within our homes and save energy. And, of course, they help make our city more beautiful.