For a lot of people, the thought of pruning their beautiful but shaggy trees, can often be a daunting task.

I think the majority of our pruning problems are more a result of not having a pruning plan before we start cutting, more than anything else. Often people will just start cutting and continue cutting without a clear direction of where they are headed with the pruning. I try to prune each year and try to not let a plant get to the point where it needs lots of material removed all at once.

There are several reasons trees and shrubs are pruned, and they include:

  • Maintain or improve plant health
  • Prevent damage or injury plant may cause
  • Maintain or control plant size
  • Improve fruit production
  • Create better plant shape
  • Create a special look for a plant

Sometimes we get hung up on the right time to prune, which is usually during the dormant season, mid winter through early spring. Most trees and shrubs, however, can be pruned throughout the year without damage, even if there are preferred times when they should be pruned.

During the active growing season, try to limit pruning to later in the summer; it will help reduce excessive growth. My big concern is making sure there is sufficient time for the tree or shrub to harden off before cold weather, allowing soft tissue time to heal and prevent cold injuries during the winter. When buds form on flowering shrubs or trees, and whether the buds form on new growth or older growth is another concern.

Another important issue on timing would be if pests, such as Sequoia pitch moths, are attracted to the pitch given off by the healing process on evergreens.

Why prune:

  • Damaged branches need to be pruned to prevent injury from falling branches and to promote tree healing.
  • Branches that grow toward the center, parallel to, or cross over other branches and reduce light and air flow, which is necessary for optimal growth.

To create a desirable shape with good limb angles that prevent breakage under a snow or fruit load.

The biggest mistake I see are people making too many heading cuts, which is cutting the tip or end of a branch off. This is basically telling the tree or shrub to send out lots of lateral (side) growth. It should be used mainly on young trees that need to establish structure and shape. It encourages more growth and in all directions, especially when it’s new wood from the last season.

A better choice on established trees and shrubs is a thinning cut to remove the branch back to a main limb. This will create less uncontrolled growth to deal with next year, while opening up a tree for air flow or to allow for more light.

Too often pruning is an attempt to contain the natural growth of a tree or shrub into too small of space. A better approach is to plan for the long-term growth and size of a tree and make sure there is adequate room before planting it. It’s also fine to overplant an area for a fuller look, as long as trees or shrubs are removed as the space needs require. Just because it looked good when we first planted a tree or shrub, doesn’t mean it will look good forever. I will often remove a tree or shrub that has outgrown its space to make sure I have the light and airflow I need in a landscape.

So take the time before you prune — make a plan to prune rather than just making cuts.

A WSU Master Gardeners of Chelan County column appears weekly in The Wenatchee World. Lloyd Thompson is one of four columnists featured. Learn more, visit or call 667-6540.