Hello! I just moved into a house with an old boxwood hedge growing. It looks like it was once pruned to hedge shape but has not been pruned for maybe a few years. Is it too late for me to shape it this year? Or should I wait until spring? Thank you!
Thank you for contacting the Toronto Master Gardeners for pruning advice.
It is a pleasure for me to answer a question that does not relate to Boxwood leaf miner! A common infestation attacking Boxwood Buxus in Toronto. By the look of your photo, your Boxwood hedge is healthy indeed – let us try to keep it in good shape!
Getting back to your question, it is not too late to prune your Boxwood. The very best time to prune is the spring, but it can be pruned at almost any time of the year except in the late fall, winter and very early in the spring when a hard frost can damage new growth. One thing to watch however is the age of your boxwood, older plants may not recover as quickly as new ones, so don’t overdo it with the pruning, go slowly so that you encourage new growth but not so you remove too much of the necessary cover. Too severe a pruning can seriously damage or even kill the plant.
I am enclosing a link from “The pruning school” which is a wonderful guide on the pruning of Boxwood, but note however it is printed in Virginia, so ignore their suggested best times to trim!
Getting back to my original comment about Boxwood leaf miner, while you are pruning your Boxwood it would be an excellent time to examine your plant for any signs of infestation so steps can be taken before any infestation gets out of control. Pruning your Boxwood and ridding it of excessive new growth will certainly help in preventing this harmful pest. I am including a link to the Master Gardeners site on this issue.