Trimming boxwood bushes also encourages healthy growth of what many consider one of the best evergreen shrubs and should be carried out annually whether they’re newer additions to the backyard or more established features of the design.  Here, we look at when to trim boxwood bushes so they thrive and bring the shape and structure desired to the yard.

When to trim boxwood bushes

While boxwood isn’t among the best fast growing hedges, it’s nevertheless important to maintain it by trimming. While boxwoods can, in theory, be clipped at any time of the year, doing so in fall doesn’t allow new growth to harden off before winter.  Bear in mind when trimming boxwood bushes that you should always take care to sanitize tools, disinfecting them before and after the task to minimize the likelihood of spreading disease. This is when to trim boxwood bushes.  

Trim boxwood bushes in spring

Trimming boxwoods into shape is best undertaken in the spring. But there is an exception. ‘Trimming stray branches and thinning cuts can be done anytime during the growing season,’ say the experts at the Chicago Botanic Garden (opens in new tab). Trimming boxwoods in spring before they begin to flush will remove old winter color and any burned tips. Trimming at this time of year ensures new growth will appear soon and stimulates it, too. ‘Doing so in this time frame also minimizes the risk of the plant being affected by diseases,’ says expert Charles King Sadler in a tutorial for the European Boxwood & Topiary Society (opens in new tab) (EBTS).

Later trimming for boxwood bushes

If you want to shape boxwood because you’re growing it as topiary, mature plants can be trimmed after the spring flush. Be mindful, however, that the growth that results could be damaged by early frosts.

When to trim boxwoods according to their age

Trimming young boxwood plants in spring will encourage bushy growth during the first few years of growth, so it’s worth scheduling trimming into your diary for these shrubs.  Older boxwood plants that have been neglected can be pruned hard in spring. However, it’s important to do this in stages over several years, as pruning more radically can jeopardize the plant’s health.  If you’re planting boxwood, always bear in mind the characteristics of the cultivar and whether it’s compact, upright or spreading to avoid the need to trim excessively.

How late in the season can you prune boxwoods?

‘The latest time for you to trim your boxwoods is during late spring,’ says Joe Taylor founder of home improvement and garden publication PlumbJoe (opens in new tab).  ‘Trimming during this period will allow the tips of your boxwood bushes to fully harden off before winter. Every time you trim your boxwood, new growth appears. The growth will need time to grow and get stronger to prepare itself for colder temperatures.’

Does trimming boxwoods promote growth?

Trimming boxwoods promotes growth. ‘Pruning your boxwoods helps them maintain their shape. It also helps promote new and healthier growth,’ explains Joe Taylor. ‘Boxwood bushes will continuously grow, however, at times, an overgrowth can cause the plant to become unhealthy. Trimming will help you cut off any dead branches and leaves, providing more room for the new growth to blossom.’