When To Trim Cedar Trees: Guide To Pruning Cedar Trees In The Garden

trim cedar
trim cedar
(Image credit: Flavio Vallenari)

True cedars are forest giants, growing up to 200 feet (61 m.) tall. You might think that a tree of that size could tolerate any type of pruning, but nothing could be farther from the truth. Some experts recommend against ever pruning cedar trees. However, if cutting back cedar trees is in the cards, proceed very carefully. If you prune too deeply into the branches of the cedars, you’re likely to kill them. Read on for information about how and when to trim cedar trees.

The Problem with Cutting Back Cedar Trees

The problem with trimming a cedar tree is that every cedar has a dead zone in the center of the canopy. The new green growth is dense. It blocks the sunlight from the older growth beneath and without light, it dies. The outer green growth does not extend very deep into the tree. If you are pruning cedar trees and you cut branches back into the dead zone, they will not regrow.

When to Trim Cedar Trees

The general rule is that you shouldn’t prune true cedars very often. While some trees need pruning to establish a strong, balanced or graceful shape, the three types of true cedars that thrive in the United States – Lebanon, Deodar, and Atlas cedar – do not. All three grow naturally into loose pyramid shapes. However, there are a few circumstances when it is a good idea to trim cedar trees. One such circumstance is when a cedar develops two leaders. Cedars are stronger and more beautiful if they have only one central leader. If your young cedar tree grows competing leaders, you’ll want to remove the weaker one. When trimming a cedar tree in this fashion, do so in early spring. Remove the weak leader at the point where it connects to the main stem. Sterilize the cutting tool before using it to prevent the spread of pathogens. Another time to start cutting back cedar trees is when you see damaged or dead branches. Prune out dead wood with sterilized clippers. If the cut should fall in the dead zone at the center of the cedar, cut it at the trunk instead.

How to Prune an Overgrown Cedar Tree

It happens. You thought your cedar would have enough room but it has filled up all the available space. That’s when you want to know how to prune an overgrown cedar tree. If your backyard cedars are pushing their allotted bounds, pruning cedar trees to contain their size must be done with caution. Here’s how to prune an overgrown cedar tree. Proceed branch by branch. Snip off the green branch tips on the first branch, making each cut above a lateral bud. Then proceed to the next branch and do the same. The key is not to go pruning cedar trees into the dead zone. Check before each snip to be sure that there will be green branches on the tip of the branch.

Teo Spengler
Writer

Teo Spengler has been gardening for 30 years. She is a docent at the San Francisco Botanical Garden. Her passion is trees, 250 of which she has planted on her land in France.