Do-it-yourself pruning guide for snow damage

The lawns in the neighborhood are reappearing, though my shady garden remains snow covered but for small areas exposed to the winter sun and beneath a few evergreens. On this sunny, nearly warm afternoon I toured the garden to take a closer look at the damage from the early February storm, the first I have been out since my struggles in the knee deep snow more than a week ago.

Over the past weeks I have witnessed extensive damage to large evergreens, notably Leyland cypress, the native eastern red cedar (actually a juniper, Juniperus virginiana), scrub pine (Pinus virginiana), and southern magnolia. Of deciduous trees, Japanese maples have been damaged most commonly and to the greater degree, a consequence of their dense and wide spreading branching. There are assorted shrubs and smaller evergreens that remain partially buried, but I have seen enough to expect that injury to most will not be substantial.

From my garden I have taken several photographs of damage and pruning that might be helpful in repairing some of the damage you’ll find in your garden. I have addressed only a few branches on a handful of plants, and will wait for the snow to melt further before undertaking the larger project. I expect that you should do the same, since there is no immediate danger in leaving this task for a warmer day.

If you are to consider taking on the project of pruning and cleaning up, you must first be armed with the proper tools. Most important is the hand pruner, the tool I have used in demonstrating the pruning cuts in the following photos. For making a clean cut bypass pruners (the blades overlap like scissors) are best. Bypass pruners are offered with an assortment of ergonomic handles, and some are gear driven to give a mechanical advantage to hands with less strength. For this task we require only a sharp, sturdy tool, since many cuts will be made and we want a crisp, clean cut. Pruning tools

Other tools that might be necessary are loppers (long handled pruners for cutting larger branches), a pruning saw (such as the folding saw in the picture), and a chainsaw (for major branches or for removing a tree at its base). In circumstances requiring a chainsaw please use caution, and if a branch is not within easy reach I would recommend a professional do the work. All cuts should be left untreated by pruning paints or sprays, and cavities left when a branch tears should not be filled. These treatments have been proven ineffective, and might cause damage.  Branch broken by snow

In the photograph above a branch of this upright growing Japanese maple has split, and the branch has broken off. The pruning cuts shown here should be duplicated as closely as possible on branches of deciduous or evergreen trees and shrubs.Pruning leaving the branch collar

In the picture above, I have placed the blade of the pruner near the base of the larger branch, but not flush with the branch. The cut is made just outside the branch collar, the area that flares out from the larger branch. Leaving this allows the tree or shrub to repair itself to cover the wound.A clean pruning cut

Above, the cut has been made, leaving the branch collar, and onto the next. Not every branch will be pruned so cleanly, as we’ll soon see.Broken azalea branch

In the example above a branch of a large azalea has split. Fortunately, in my tour around the garden I saw much less damage to azaleas, rhododendron, and andromeda (Pieris) than I expected, since their branches are somewhat brittle and often broken in handling.

The pruning cut should be made just above the next branch down from the break. In this case that is a very small branch, but the azalea will grow from the point of this cut. If I had made the cut nearer the split the branch would probably die back to the lower branch.Broken magnolia branch

In some cases a flush cut with the branch collar is difficult or impossible, as seen above on a smaller broken branch of a southern magnolia. Here, a smaller branch made the correct angle cut impossible, so a little extra bit of the branch was left. It is better to err by leaving too much rather than cutting too close.

In the photos above and below branches have broken leaving a cavity into the larger branch. I will remove as much of the branch, and leave as much of the branch collar as possible, but the break tore the collar and the wound will not heal cleanly. I don’t think that the damage is so severe to warrant pruning down to the next branch, so I’ll take the chance that this will suffice.

Thus far we have addressed only pruning cuts made with hand pruners. The process when using loppers on larger branches is similar, though it can be more difficult to prune as closely to the branch collar. On branches requiring the pruning saw, or chainsaw, it is best to make a partial cut from the underside of the branch, but not enough so that the branch pinches the saw blade.

If the shallow cut at the branch’s bottom is not made, and the saw cut is made from the top only, there is a danger that the bark will tear or that the branch will break when the cut is partially made, further injuring the tree.

If pruned properly, trees and shrubs will react to the pruning cut by sending growth from that point. With the root system of a plant several years old growth will be rapid, and in many cases the gap created by the broken branch will be filled in a few short years. Japanese maples and many shrubs will grow multiple branches from the growth buds below the cut, and could fill in for the missing branch even sooner.

In the coming weeks we’ll address other snow damage issues, in particular, branches that have been bent out of shape. Many will not immediately spring back into their original position, so we’ll work out remedies to persuade them.