Arborvitaes are a popular landscape element. There are several reasons to prune an arborvitae, such as to maintain a desired height or shape, or to remove diseased or damaged growth. Some arborvitae, however, will not need pruning as they will maintain their natural shape as they grow. It is important to understand the growth habits of this evergreen. For example, interior branches are bare and caution should be taken not to prune down to these bare areas---they cannot withstand drastic pruning. Arborvitaes should be pruned in the fall or early winter.
Step back and locate where the shape of the arborvitae is becoming irregular. Determine what branches/areas need pruning.
Examine the interior of the evergreen, before beginning to prune, noting the depth of the growth. Do not remove all of the existing growth and leave bare branches exposed.
Use the scissor-action hedge shears to slowly cut away the growth that has gotten out of shape. For minimal pruning you can use your hand pruners.
Rake up the pruned material and deposit it in your compost bin. Dispose of any diseased material.