Juniper trees come in many different shapes, sizes and foliage colors, including grays, purples, greens and gold. Due to the thick foliage and sturdy branch structure, Junipers are ideal trees for use as both bonsai trees and in topiary designs. Keeping Juniper topiary healthy and attractive requires occasional pruning.
Remove all diseased, infested, damaged or dead wood from the Juniper topiary tree. Disease and infestation may spread up the branch, causing further damage to the wood, so these branches must be removed even if they have a negative effect on the design of the topiary.
Thin the crown of the tree by cutting away up to one-third of the branches in the tree. This can be done in ball topiary. The foliage will be less thick until the branches grow back, but opening the crown allows for better airflow through the branches and allows light to reach the inner branches.
Cut off any branches that are crossed over each other or rubbing against each other. Branches that cross or rub can cause damage to each other's bark, making wounds that make the tree susceptible to infection and weather damage.
Trim the Juniper tree back to its topiary shape. If the topiary has been created using a wire form, the topiary can be pruned back to level with the form. If cut free-hand, the tree can be trimmed back into its original form by sight.
Clip small limbs back to healthy wood. You can tell healthy wood from dead wood by scratching through the bark with your fingernail. Green wood is healthy and moist, while dead wood will appear brown and dry. If removing whole branches, trim all the way back to the trunk.
Prune during the winter season when the plant is dormant. This will lessen the damage done to the tree.