The Best Time to Prune Boxwoods

Shearing

• Shearing mature, formal boxwood creates clean lines and dense growth habit. Sheared hedges are used for privacy screens and boundary demarcations. Maintain a wide base and narrow top when shearing boxwood. Top-heavy boxwood suffers from snow damage and structural defects. Shear hedges after the spring growth period. This tames and shapes unruly new growth.

Thinning

• Boxwoods are dense-growing, evergreen shrubs. Their ever-present foliage isolates inner growth from air and light. Interior growth may die back because air and light cannot circulate. This environment also encourages pests and fungal disease. Thinning out lateral growth protects boxwoods. Thin early in the growing season. Refrain from trimming your boxwood at least six weeks before the first frost. The newly pruned branches are unable to protect themselves from cold frosts.

Topiary

• Topiary are living sculptures running from ornate to simple globe designs framing walkways and entrances. Topiary requires routine maintenance and trimming to hold its shape and design. Regularly misting the plant encourages bud growth and formation. Since trimming encourages new growth, clip during the warm season. Do not trim in late summer or during cold weather. New growth does not survive frost damage. Trim indoor bonsai and topiary at any time. Avoid severely cutting back any section, as it may take years before growth returns.

Renewal Pruning

• When left unattended boxwood becomes unruly. Improper trimming, such as a narrow base and wide top, causes boxwood to topple or prone to other damage. In such cases, renewal pruning encourages new growth and structural integrity. Boxwoods are generally unable to recover from excessive growth problems and renewal pruning is often unsuccessful. Still, if taking this drastic corrective action, prune back no more than 1/3 of the plant in the course of several years. This pruning is best done during the late winter and early spring.