Pruning Shrubs In Winter

If winter’s the best time to prune deciduous trees it should be the best time to prune deciduous shrubs as well. Right? That’s one of those questions that I have to answer, “It depends.” It depends on whether the shrub flowers in early spring or in late spring or summer.

Early flowering shrubs like forsythia or lilacs shouldn’t be pruned until after they flower. These plants flower on old wood, specifically, last year’s growth. The buds that will burst forth into colorful flowers this spring were set last fall. Pruning may remove all or some of the flowers, so you won’t get to enjoy the beautiful blooms this spring. Wait until after they’ve finished blooming to prune these shrubs.

Late flowering shrubs like hydrangeas or butterfly bushes bloom on new wood – on growth that’s new this spring. You can prune these plants now without affecting their floral display this season.  Look closely at the branches before grabbing the pruning shears. Shrubs that bloom on new wood won’t have buds on the old branches. If you prune these shrubs later in the winter or in early spring be sure you just prune old wood. It’s easily identified, usually by its gray, weathered color. New growth will look fresh and have buds on it.

Some shrubs flower but their flowers aren’t showy. They’re planted primarily for their foliage. They’re best pruned before new growth appears and before they leaf out. These shrubs are ideal candidates for winter pruning. Like trees, deciduous shrubs bare their skeletons in winter, so you can see the structure.

Begin by removing any broken or cracked branches. Next remove any branches that are crossing or interfering with others. With all the errant branches out of the way, you can begin shaping the shrub. If you don’t remember what an overgrown shrub should look like, you’ll surely be able to find photos on the internet.

As you prune, keep in mind that woody shrubs are the same material as trees. The roots take up water and nutrients and distribute food the same way trees do. When removing branches, avoid leaving stubs. Ground level is the best place to make cuts. If that’s impossible, the next best place is at a junction of two branches or just above a leaf bud. If the shrub is big enough to have branch collars (swollen tissue where a branch is joined to a larger branch), leave the collar rather than making a flush cut. Don’t paint or treat cuts; let nature take its course.

Evergreens shouldn’t be pruned in winter, except to remove broken branches or in other emergency situations. Then any shrub should be pruned immediately. The best time to prune evergreens is right after they’re finished pushing new growth but before the new growth has set. New growth will be lighter green and softer to the touch than old growth.

Unlike tree pruning, shrubs pruning can be a do-it-yourself job. If you’d rather leave it to the professionals, though, our arborists would be happy to prune your shrubs.