To maintain the health of your trees and shrubs all year round, it’s important to prune and water them at the appropriate times.

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Pruning

A tree or shrub may need pruning for various reasons:

• To remove dead or diseased foliage/branches.
• To remove hazardous branches for safety.
• To improve air circulation, reduce weight of crown and to rejuvenate growth.
• To ensure healthy, vigorous plants by balancing growth, flowering and fruiting.

When to prune

The best time of year to prune most trees is during the dormant season of late fall or early spring—before bud break. Pruning trees when they are dormant:

• Minimizes sap loss and subsequent stress to the tree. 
• Reduces the risk of fungus infection or insect infestation. 
• Minimizes the risk of pest problems associated with wound entry. 
• Allows trees to take advantage of the full growing season to begin closing and compartmentalizing wounds. 

Deciduous trees

Prune deciduous trees when the leaves are gone so you can see how your pruning will affect the shape of the tree. Dead or diseased branches can and should be removed at any time.

Coniferous Trees

Evergreens such as fir, pine and spruce trees require little pruning, unless you want to control their size or improve their fullness. Cutting the candles back halfway, before the needles unfold, will keep the tree more compact.

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Watering

Tree watering is one of the most important things you can do to ensure the health and vigour of your trees. However, like pruning, it is best to hold off on the watering until your trees having gone into total dormancy.

You should stop watering your trees in mid-September. Trees are still actively growing in September and added moisture will slow the onset of dormancy, which is the process that allows trees to prepare for winter.

Deciduous Trees

Start watering deciduous trees again in late October or once they have lost all of their leaves. Deciduous trees need a final heavy soaking so the root system is moist when it freezes. This ensures that the tree is not in need of water going into winter and will also be available in the spring when the ground begins to thaw.

Coniferous Trees

Evergreens definitely need to be watered in late fall. These trees do not go into full dormancy and will be constantly using water anytime the temperature gets near zero degrees Celsius.

Use low pressure to water deeply and eliminate run-off. Let the water gently soak into the soil and ensure the soil is moist when the ground freezes. Mature trees should be watered at the drip-line while new trees should be watered at the root-ball.

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Fall yard maintenance

Focus on getting your yard ready for winter by raking up any leaves from trees that may have been infected with pests or disease. If you leave any vegetation from infected trees on the ground, the insects or fungus will overwinter in the ground at the base of the tree and will be there in the spring.

Apple Maggots

Be sure to make apple picking a key part of your fall clean-up routine. It is imperative that all apples are picked off the ground to reduce apple maggots from overwintering.

Apple maggots (Rhagoletis pomonella), are a pest fly native to North America, and are a serious pest of apples in Canada. They were identified in the Edmonton area in 2005. Learn more about Apple maggots.

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Frequently asked questions

Further information: