Trimming trees: Canopy-Cleanouts

Photo by Liberty Tree Service.
This tree was in need of trimming, including a canopy-cleanout.

Whether you like your trees with really low canopies that almost touch the ground or with high canopies that make it easy to walk and mow, everyone should keep their trees trimmed. Properly trimming your trees on a regular basis (I recommend at least once every two years) provides many benefits to the trees, to the surrounding vegetation and to the homeowner.

Smaller trees can usually be trimmed easily by the homeowner. Larger trees may require the knowledge, tools and skills of a professional, but proper tree trimming will result in healthier trees and that means you reduce your risk of losing your trees and possibly costing yourself more money in the long run when you are forced to have a dead tree removed or a sick tree treated.

The Interior Canopy

When we in the tree care business talk about trimming trees, we may be referring to the removal of low hanging limbs in order to make movement around the trees easier. We might be referring to the removal of limbs touching a roof or hanging over power lines. However, in most cases, when a plantsman or arborist refers to trimming trees we are referring to the removal of dead wood and stubby growth on the interior of the tree's canopy. It's what I call a canopy-cleanout.

Allow Wounds to Heal

One of the benefits of a canopy-cleanout is that all the dead wood is properly cut and removed. This allows the tree to begin healing those wounds and internalizing them. Dead wood should never be left attached to a tree. This keeps the tree from healing its wounds and allows decay to spread further into the main limb or trunk while also leaving a portal for boring insects to enter the tree.

This is the same tree pictured above after a canopy-cleanout.Photo by Liberty Tree Service.

This is the same tree pictured above after a canopy-cleanout.

The Welfare Line

Another reason why canopy-cleanouts are so beneficial for trees is that they dramatically reduce the amount of foliage on the interior of the canopy. The purpose of a leaf (or needle) on a tree is to transform sunlight into energy for the tree in a process known as photosynthesis. The leaves on the interior of the canopy receive almost no sunlight, so they are not contributing to the tree but they do take energy from the tree until they eventually die. I refer to this interior growth as the welfare line of the tree and removing this stubby growth frees up the tree's resources for healthier outward growth.

Air Flow

Most folks around Ellis County don't have much of a problem with fungus, but it does occur, especially when we have a lot of moisture. Fungus needs three conditions to thrive: moisture, warm air, and stillness. Cleaning out the interior of your tree's canopy can greatly reduce the risk of a fungus because it increases the air flow through the canopy and allows the canopy to dry out faster.


Many people have problems getting grass to grow under a large tree. In many instances, even shade tolerant grass like St Augustine won't even grow because the shade is so dense. A good canopy-cleanout will thin out the dense shade and allow more sunlight to filter down to the ground below while also allowing more sunlight into the interior of the canopy to help dry it out.

A Growing Tree is a Healthy Tree

All of the reason I have discussed thus far are good reasons to keep your trees properly trimmed, but the number one most important reason for having a regular canopy-cleanout done on your trees is that it promotes growth. The best way to keep your trees heathy is to keep them growing. Good fertile soil and a proper trim from time to time and you can stop worrying about the pesticides and fungicides for the most part.

Well, now you know why it is important to keep your trees trimmed. In my next article I will discuss the proper way to cut a limb. If you have any questions you would like to have answered about tree care or gardening send me an email at and I'll try to answer those questions in future articles.