It’s a weird sort of time warp. These COVID-19 days seem to drag, despite our previous longing for enough time at home to get everything done. At the same time, who can believe Christmas – and the new year – are practically here? Time has flown as we’ve learned to deal with the uncertainty and change of lifestyle we’ve experienced since March. Time drags but flies at the same time…go figure.
Why not take on a new project after the holidays? It will help with the emotional letdown of holiday aftermath and make the short days go faster. The new project is…wait for it…Pruning!
The cold winter and early spring days are perfect for pruning trees and shrubs that bloom on “new wood.” New wood is, obviously, the brand-new, just grew, twigs. Roses are a great example (many others listed below). Since the old, including last season’s branches, won’t provide bloom, their branches are fair game. The cooler temperatures and plant’s dormancy make it easier on the shrub to withstand pruning and it’s certainly easier on us than hot, humid days.
Those plants that bloom on old wood will have to wait for their “haircut” until after their bloom. Pruning them just after the bloom will allow them to grow some new wood, which, by the following spring, will be “old” wood, so it’s best to prune them on a cooler, overcast day as soon as possible after their bloom period. If you do prune them in the winter, they’ll be healthy, they just won’t bloom in the spring because you cut it off. (list of common “old wood” plants below).
Whenever you do prune, follow these guidelines:
Prune on a mild, perhaps overcast day. This allows the plant to heal over its wounds before a tough freeze (below 20 degrees) or wild winds, which could damage the tender spots.
Remove dead or diseased wood. This can be done any time of year, but certainly should be done now.
Cut branches to the “collar.” Collars are where the branch attaches to the main branch or trunk and is slightly wider than the rest of the branch (collars are sometimes called “nodes”). Never cut the actual collar, as the collar will heal easily, while removing it will damage the branch it’s attached to, opening the way for disease. If you wish to remove an entire shoot, cut close to the ground but not at ground level, which would allow crawling critters easy access to the wound.
There are several goals achievable with a good pruning.
Improve the plant’s shape. Plants will tend to grow their branches unevenly. Standing 5 to 10 feet back from the plant, study it with an eye to removing branches that are “aimed” in the wrong directions or are making the plant look unbalanced. Now stand back again, look at the plant with its new shape. What else needs to go? Step forward and remove what needs to go and stand back to review it again. Repeat the “stand back, review, then cut” process until the plant has achieved the best shape or until you’ve removed a third of its branches.
If you want a conical plant, “Christmas tree” shape, enhance the “central leader.” The central leader is the strong trunk that supports all the branches, which get longer toward the bottom of the plant. Often you must create a central leader or replace it if the original is damaged. To create a central leader, study the plant to determine which of the upright branches is closest to the center and remove all competitors. The plant will look a tad odd for a year or so if you’ve created the central leader out of nothing, but thereafter it will have a lovely Christmas tree shape you’re looking for. If you study a live Christmas tree, you can see where competing “leaders” have been cut back to improve the shape. Thereafter, prune the “edges” to maintain the proper shape.
As a rule, don’t remove more than a third of a plant’s branches. There are some exceptions here. Sometimes shrubs are horribly overgrown, and your best bet it to cut it to within 6 inches of the ground, all at once. This is actually a great thing to do with Rhododendrons, who tend always to have leaves only at the tips of their branches, and grow the branches longer and longer, so that eventually there’s an enormous plant that’s utterly bare behind a facade of leaves. If it’s gotten too large, after the bloom, cut the shrub very close to the ground. It will come back happily with amazing speed and be much healthier. Lilacs and crepe myrtles can take the same treatment; this will give you fuller, healthier, plants, with bloom where it can be seen without craning your head back to stare at flowers up in the sky.
Open up the center of the plant. Consider that wind should be able to swoosh through the plant without hindrance (this is critically important with large trees that could be toppled by wind, but you probably should hire experts for those). Opening the center allows the plant to grow for sunlight closer to the trunk rather than endlessly lengthening their branches, which will result in a fuller looking shrub/tree (and probably allow you to skip pruning it again for at least a few years). Look for branches that cross the center and remove them.
Remove crossed branches. Movement in the wind will injure the bark on the branches. On young trees, remove branches growing at extreme angles as these can easily break in strong winds.
Use the right tools! Hedge sheers are great for yews but shouldn’t go near flowering shrubs. Hand pruners will remove small branches up to 1/4 inch while loppers will remove branches up to several inches across. Larger branches should be removed with a saw. Power hedge trimmers are fabulous for the job they’re named for (but also do a great job on ornamental grasses that need cutting back in the spring).
It almost goes without saying – clean your tools after each plant (if the plant is obviously diseased, after each cut). Cleaning keeps disease from spreading. And – sharpen them. Even shovels should be sharpened regularly; your pruning tools more so.
Prune In Winter or Early Spring – Almost all woody plants
Evergreens – prune trees for shape; shrubs need open centers and shaping
Fruiting trees and shrubs
Oaks (only prune in full winter, not early spring through fall)
Azaleas
Crepe Myrtle
Roses (cut canes with girth greater than 1/2 inch, prune for height. Remove all growth that comes from below the rootstock graft)
*Hydrangeas (Peegee and Smooth, prune for shape and improved flowering)
Prune after Bloom
Rhododendrons
Forsythia
Lilac
Star Magnolia
Oakleaf Hydrangea
Mountain Laurel
Camelia
Dogwood
Redbud
Flowering cherry, peach, plum, pear, crabapple (flowering means no fruit)
Viburnum
*Hydrangeas. (Bigleaf and Oakleaf bloom on old wood)
*Hydrangeas are tricky. While Peegee and Oakleaf varieties are easy to spot, it’s tougher to figure out Smooth and Bigleaf. If you don’t know which you’ve got, study the leaves. Smooth has rounded leaves with a small point, the underside is paler than the top. Bigleaf will often change its flower color because of pH (acid=blue, alkaline=pink, neutral=white) and its’ leaves are serrated, glossy, and dark green.
Happy Pruning!
Maureen Rice is a Master Naturalist living and writing in Talbot County.