How to Prune Red Cedar Trees


Western red cedar, Thuja plicata, is an evergreen conifer hardy to USDA Zone 5 Landscapers use it in gardens as a background or shade tree, and it is especially valued for its graceful, drooping branches and reddish bark. Well-adapted to wet soils, it will grow under ordinary garden conditions and even tolerate a bit of drought once established. It may need occasional thinning to allow more light to reach the ground or pruning back from walls and fences if planted without allowance for the length of the curving branches.

Step 1

Remove any branches touching walls or fences. Either cut back to the main trunk of the tree, using a pruning saw, or to a side shoot, using a lopper or pruning shears. Leave no more than a quarter-inch of stub beyond the growing branch that remains.

Step 2

Cut away any branches that are producing too much shade. Start from the bottom of the tree and work up the trunk, removing small branches at the trunk and leaving the major framework of the tree.

Step 3

Prune side branches from the remaining limbs, leaving some green leafy shoots to continue growth.

Step 4

Cut off some of the smallest branches or twigs, using pruning shears. You can reduce the amount of shade without changing the basic shape of the tree by removing these small bits of growth.

Tips and Warnings

  • Topping a mature cedar is never appropriate, even if it is getting too tall. Either thin the branches to allow light and air to move through, or remove the tree and plant another type.

Things You'll Need

  • Lopper
  • Pruning shears
  • Pruning saw


  • Conifer Society
  • Univeristy of California Cooperative Extension
Keywords: western red cedar, pruning conifers, pruning red cedar

About this Author

Over the past 30 years, Mara Grey has sold plants in nurseries, designed gardens and volunteered as a Master Gardener. She is the author of "The Lazy Gardener" and "The Complete Idiot's Guide to Flower Gardening" and has a Bachelor of Science in botany.