On a sunny mild day early in the year, I bundle up and tromp outside to begin winter pruning of my shrubs and small trees. Despite the cold, this is a garden chore I relish. I love being out in the brisk fresh air. I revel in the lengthening daylight and spending time in my garden after December’s hectic, short days.
Pruning is part science, part art. It is done primarily to improve the health of shrubs and trees. If you find yourself repeatedly pruning or shearing (or wanting to prune or shear) trees or shrubs to reduce their size or keep them from encroaching on your house, walkway, or driveway, consider removing the plant and replacing it with something more suitable since repeated whacking isn’t good for the plant and, certainly, you have better things to do with your time!
My pruning tools include sharp hand pruners, sharp loppers, leather gloves to protect my hands, and a tarp for gathering trimmings and dragging them to the brush pile.
If you want to do some winter pruning, keep the following points in mind:
- Spring-blooming shrubs like forsythia, lilacs, quince, viburnum, azalea, crabapples, and rhododendron have already formed their spring flower buds (they formed them after blooming last spring). Those buds are just waiting for longer days and warmer temperatures to pop open. Prune those spring bloomers now and you’ll be cutting off those flower buds, reducing the spring show. If you don’t want to reduce the spring flowers, wait to prune these plants until just after they are done blooming and before they have formed next year’s flower buds.
- Some plants “bleed” sap heavily when they are cut. Maples are notorious for this. After all, maple sap is what is tapped in winter to make maple syrup. These trees are better off being cut in the fall, right after they go dormant.
- Don’t attempt to prune large trees yourself or any tree or shrub that requires you to climb a ladder. Hire a certified arborist. To find one, visit the International Society of Arboriculture website.
- It’s ok to remove up to about a quarter to a third of the plant’s living branches. If your plant has not been pruned in a long time, you may need to spread the pruning out over 2-3 years.
- Aside from the tools listed above, the best tools you can use for pruning are your eyes. Put down your pruners periodically to look at what you are doing. This helps keep you from cutting too much or ruining the plant’s shape.
Ready to tackle your pruning project? Here are the basic steps:
- Begin by walking all the way around the plant at least once. Note how it grows and its natural form. Does it have an upright, horizontal, or weeping habit? Does it grow with a lot of branches at the base (called a suckering habit) or does it branch from one or two main trunks (like a tree)? Overall does it look balanced, or is it lopsided with more or less growth on one side?
- Trim out dead, broken branches first. Cut back to where the branch intersects with another live branch, or all the way to the ground in the case of suckering shrubs. If the plant has not been pruned in some time, it can take quite some time to remove all the dead branches. In fact, cutting dead wood should make up 80% of any pruning job.
- Once all the dead wood is out of the way, you can start to see the natural form of the healthy plant. The next step is to clear out its interior to improve light and air circulation. Trim branches that are crossing back and growing inward, toward the center of the plant. If the plant’s habit is suckering growth from the base, thin a few of the biggest interior branches at ground level.
- Step back and observe the plant’s natural overall shape. The last little bit of pruning involves a few snips to enhance that natural form: thinning any overly dense areas or trimming the odd wayward stem or two.
Congratulations on a good pruning job!
Below are photos showing renovation of overgrown spireas I helped a friend with. Left–the old beautiful spirea were engulfing the garden before pruning. Center–after pruning, the shrubs are a much more manageable size while retaining their graceful natural shape. Right–spirea grow from the base, so here you can see the cuts we made and remaining branches.