How to Prune Boxwood

Boxwood garden

Boxwood is a standard in many gardens and if cared for correctly it can last for generations. Pruning boxwood is an essential part of that continual care. Pruning not only keeps the shrubs from looking untidy, but it also stops them from becoming vastly overgrown. Large overgrown bushes need slightly more drastic pruning, but even that can be done by a homeowner if you take some basic things into consideration.

Things You'll Need

• Pruning shears
• Loping shears
• Tree saw

Instructions

1. Get the timing right. As with most shrubs, the time to prune is critical to success. Boxwood does flower, but the flower is insignificant and as most people grow boxwood as a design feature in formal gardens, rather than a pretty flowering feature, timing to allow blooms is not necessary. However, pruning boxwood in winter can increase the likelihood of dampness gathering between joints in the lower sections of the bush, and this can create a site where dampness and then fungal problems proliferate. So major pruning should be performed in late winter or early spring.

2. Clip to retain shape. Clipping can be done at any time during the growing season. Most shrubs, including boxwood, do put on a rapid growth period each spring, so let this phase of growth slow down before clipping. Using regular pruning shears, take each stem and prune back. Look for joints in the stem where another set of leaves are coming out, and prune to just above this junction.

3. Rejuvenate a mature boxwood. Knowing how to prune boxwood to rejuvenate a mature specimen is different from simple clipping. Large overgrown bushes can take major reduction, but you do take a risk when you do so. There are two schools of thought regarding a major pruning of this shrub. Method one prefers that you prune the boxwood in stages, and thus cause less stress on the shrub. You do keep the majority of the shrub which is aesthetically more pleasing, but continual major pruning over several years to reduce the height exposes more stems to rain, each of which can suffer from infections at the cut site. Consequently the whole shrub is under a state of stress, albeit less stress, for an extended period of time. Using regular pruning shears, and sometimes a larger set of loping shears, take the outer stems back to a much lower level. Make sure that you cut at a junction between two stems so that regrowth can occur quickly.

4. Understand method two for pruning a shrub. This involves taking most of the top growth off, and letting the remaining basal stems regenerate. This way does work, but has drawbacks. Large, thick branches are tough to cut cleanly giving an inherent problem of infection. Also the lack of canopy allows more moisture onto the crown and surrounding lower junctions which, because they are wider, can create pools of standing water. The upside is that you can reduce a 4 foot boxwood to just a foot or 2 in height, and although it will look rather ugly in the first year, most of the shrubs will fill out by year two or three. You will need to use a pruning saw to cut through larger stems. Take out outer stems first, then work on the inner and lower ones. Leave an overall shape that will regrow to an even shape.

Resources

• The American Boxwood Society