How and When to Prune Boxwood for a Healthy, Perfectly Shaped Hedge Year-Round

Boxwood is an incredibly versatile and low-maintenance evergreen shrub that can transform your yard into a year-round focal point. Its rich greenery provides structure and color, making it a favorite choice for landscaping enthusiasts. Whether you're looking to create lush hedges, define borders, or enhance the visual appeal of your outdoor space, boxwood is up to the task. Plus, it’s not just beautiful, it's deer-resistant and cold-hardy, making it a fantastic option for gardens in various climates.

Boxwood shrubs can be trimmed and shaped into various forms, enhancing the character of your garden space. However, some gardeners hesitate to cut the hardy evergreen because they worry it might be difficult, do not know when to trim, or do not know how to do it properly. Below, professionals explain when to trim boxwood and offer tips for shaping a healthy, thriving plant.

When to Trim Boxwood

The best time to trim boxwood is from late spring to early summer, according to Kristi Baldini of Windswept Gardens in Bangor, Maine. She advises trimming boxwood once the new growth has started to harden off. Avoid trimming boxwood too early in spring to allow time for new growth to emerge.

Minor touch-up pruning, like removing stray shoots, should be done in mid-summer, Baldini says. If necessary, very light pruning can occur in late winter before growth resumes; however, it’s best to postpone this unless you are shaping an overgrown plant.

How to Trim Boxwood for Size and Shape

Trimming the boxwood for size reduction and shape maintenance is a straightforward process that varies in approach for each gardener. Follow these tips to successfully trim your boxwood for the desired shape and size.

1. Assess the boxwood: Before cutting, have a clear plan for the shape and size you want to maintain. Consider the natural growth habit of your boxwood variety and overall landscape design goals.
2. Remove dead branches: Remove dead, diseased, or damaged branches. Dead branches will be dry, brittle, and easily break off. Removing dead and diseased branches prevents the spread of diseases and promotes better airflow to the plant.
3. Shape the plant: Prune any stray branches that are noticeably protruding from the plant. Lightly trim the top and sides to help maintain the plant's shape and achieve a neat appearance. "Cut just above leaf nodes to encourage branching," notes Baldini.
4. Thin interior or crowded areas: Selectively remove branches from the inside of the plant. Baldini notes that this improves airflow and helps prevent diseases, especially boxwood blight. "Avoid cutting into bare wood, as boxwood doesn’t bounce back well from hard pruning into leafless stems," says Baldini. (Bare wood is limbs with no leaves)
5. Water well: After pruning, Baldini encourages giving your boxwood a drink of water to help it recover.

How to Prune to Remove Damaged and Diseased Branches

Trimming dead and diseased branches will improve your plant's health and prevent the spread of disease. Regularly pruning these branches makes future trimming sessions easier.

1. Identify problem branches: First, identify any branches that are broken, damaged, discolored, or dead. For diseased branches, check for symptoms, such as leaf spots, blackened leaves, drooping leaves, changes in leaf color, girdling, or loose and peeling bark. If you suspect a disease, disinfect your tool with isopropyl alcohol before and after each cut.
2. Locate a leaf node: Trim branches just above a leaf node or bud at a 45-degree angle to encourage healing and prevent water accumulation.
3. Discard the cuttings: Remove the diseased cuttings from your yard. Do not put them in your compost pile, as this can spread disease.
   

Pruning to Thin Boxwood

Thinning boxwood is important for restoring a lush and balanced appearance. Because boxwoods are prone to fungal diseases, thinning helps promote better airflow to the interior, particularly in densely populated areas of the plant. Aim to remove about 10 percent of the branches when thinning your boxwood.

Using clean, sharp pruners, carefully snip stems from dense foliage areas, especially the center of the plant. The boxwood stems provide essential structural support for the shrub, holding up its leaves and branches. It is crucial to remove branches evenly throughout the entire plant. The goal is to allow sunlight to penetrate the inner branches and to improve airflow. 

How to Cloud Prune

Cloud pruning can transform your boxwood into a work of art. "Cloud pruning creates soft, rounded 'puffs' for a natural, sculpted look," says Ryan and Barry Messinger of Messinger’s Hardscape Landscaping and Design, LLC. This creative method of pruning trees is relatively easy to achieve but may take time to perfect. The best time to cloud prune is late spring to early summer, using clean, hand-held shears for precision.

1. Remove unwanted growth: Remove unwanted branches and growth from the trunk and main branches.
2. Shape the clouds: "Trim boxwood into separate rounded shapes, leaving space for light and airflow," says Ryan and Barry. Work with the plant’s natural branching patterns to create an interesting cloud-like shape.
3. Take breaks: Step back regularly to check the shape and avoid cutting into old wood. Taking time to pause and evaluate your creation will help ensure you stay on the right path.
4. Trim the tips: After achieving the desired shape, trim the tips of the branches to promote more branching and create a 'puffy' cloud-like appearance.

When Not to Prune Boxwood

Avoid pruning boxwood in late summer or fall, as this can trigger tender new growth that may be damaged by frost, says Baldini. Also, do not prune during extreme heat and drought. Pruning or trimming boxwood in extremely hot and humid weather can harm the plant and expose interior branches to leaf burn.