When and How to Prune Boxwood Shrubs
It was late fall last year, around mid-November. We had yet to endure a hard freeze which is 4+ continuous hours of sub-freezing temperatures. I saw a local landscape company trimming a neighbor’s boxwood shrubs. That kind of surprised me. They were really going after them.
Boxwoods are known for handling extensive pruning. You can trim boxwoods almost any time of the year. But heavy pruning in fall or early winter could cause issues. Any new growth may not become cold-hardy enough before the next frost. This can not only cause the new growth to die but also makes your whole plant more vulnerable to frost damage & other diseases.
Even holly shrubs, like boxwoods, go into a dormant state during the coldest weather. New growth will stop. Right at the end of the worst cold weather is the best time to heavily prune boxwoods.
So as handy as it may be to prune your boxwoods in mid to late fall, extensive pruning should be limited to late winter.
How to Prune Boxwood Shrubs
If you have boxwood shrubs that have grown too big and are crowding each other out, or even blocking views, hedge clippers won’t do the trick. You need those heavy heavy duty pruning loppers. They’re usually $20 to $30 at a local hardware store. Or, maybe a nice neighbor will let you borrow theirs.
Have at it! I am notorious for over-doing it once I start pruning. With boxwoods, it is okay to prune back far enough where you have cut away all the foliage. That means you will have naked branches. This one of the main reasons we recommend you wait until late winter, a few weeks before the weather warms enough for new growth to emerge.
For occasional clean up thru the year, use hand shears to cut away any dying or dead wood from the interior of the shrub. This is important to maintain and keep good airflow. Mild pruning with shears to just keep it to shape is also fine to do any time of the year.
Another key is to prune your shrubs on dry days. Wait until any morning dew is gone. The exposed ends of pruned shrubs are susceptible to fungus or other issues. Being wet just makes them even more vulnerable.