Conifers don't need much trimming except when you use them as hedges or topiaries. Learn how and when to prune.
There are several reasons to prune a cedar hedge: to manage insect populations, to improve foliage density, to control the size and shape of the hedge, and to enhance the value of your property.
Trimming to ensure healthy growth
Take out your pruning shears in the spring to cut out dry, dead or broken branches.
Maintenance and shape pruning
You can trim a cedar hedge most anytime of the year without harming it, but there are better times, and that would ideally be between June 20 and August 1, with a larger window from May until late September.
What to prune
During the initial years after planting, only prune the sides, maintaining a base that is larger than the top. A cone-shape or pyramid-shape for the hedge allows the sun to penetrate and ensures better resistance to the weight of snow. Thus, the base will be twice as large as the top.
Topping involves trimming the tops of your cedars when they have reached the height you want, or the maximum height allowed by municipal by-laws. Aim for a rounded shape.
- Identify new growth - this will be a lighter green than the rest of the tree.
- Trim 1/3 or a maximum of half the new foliage. Cedars are not able to produce new growth on old wood.
- Keep part of the new growth so that the cedar continues to grow and fill out.
This type of pruning is done in the spring or in the fall on hedges that have been ignored for a number of years. In order to avoid permanent and significant damage to the hedge, it is advisable to have the work done by an experienced tree technician.