How to Prune Evergreen Trees and Shrubs

The best thing about evergreen trees and shrubs is that they last all year long, consistently making a beautiful backdrop for the yard in every season. And not only do they survive throughout the year, part of their appeal is how low-maintenance evergreens are.
 
With thicker, needle-like leaves, evergreen trees and shrubs have dominant vertical stems that shape the plant for a strong life, requiring little pruning and upkeep. However, light trimming once a year - best before the growing season begins - is how to keep evergreens in healthy condition, and in the shape and size you desire. 

 

Why to prune

Pruning evergreen trees and shrubs shouldn't be done more than once a year or recreationally, as they don't replace growth or need regular trimming. However, if the overall look or size of the evergreen needs some editing, or if the plant shows sign of poor health, you should prune the plant to keep it in good condition. 
  • Aesthetic. Evergreen trees should be pyramidal in shape, which can be threatened if there are multiple branches shooting out of the tree, causing it to look unruly and uneven. Trim back rogue branches so they fall in line with the apex-like shape of the tree. 
  • Size. If you find evergreens growing faster than expected and growing into buildings or other plants, trim the branches once a year before the growing season to the desired size and shape.
  • Health. To maintain and extend the life of your evergreens, keep an eye out for dead, diseased and damaged branches. Disease can move quickly through the plant and lead to plant death. Spot disease by looking for sunken dead patches on the bark and brown or yellow wilting leaves.

 

What to prune

If you have a large tree, it's best to arrange for a tree service company to properly trim evergreens and prevent injury. However, if you have a smaller, more manageable plant, you can trim it yourself. If your plant has two leaders - which is the vertical stem at the top of the tree - trim off one of them to prevent multiple leader development. As this will prevent the tree from having poor attachment and breaking off later in its life. If the tree or shrub has dead wood on the branches, trim it off immediately by cutting them back to healthy branches. You can identify dead or damaged branches by their lack of green foliage or live tissue under the bark. To detect if there is live tissue under the bark, scrape off a small area of the outer bark on a branch to inspect for dryness, which indicates it is dead. 
 
To avoid any mistakes or destroying the tree and shrub, never remove the main vertical central stem (the part all the branches grow out from) or healthy lower branches on the tree as this will change the pyramid-like shape and alter the overall look of the plant.

How to prune

The first time a tree or shrub will need pruning is when it's planted. When a young plant is pruned and trained to grow properly early in its life, it will need minimal upkeep in later years. If you need to trim for aesthetic or health reasons, prune while the evergreen is dormant in the early spring before new growth starts or when they are semi-dormant during mid-summer. When trimming, use a lopper to trim the tips of the branches lightly, just above a leaf bud so you are not left with a stub. If there are fully-developed green leaves on the branch, do not cut it completely off, as it will not grow back; only cut off dead or diseased branches or branches you're ready to part with indefinitely.