Pruning Hedge

February has arrived, and if you didn’t get out to prune anything in January, then you can easily do so now. We’ve allowed the winter injuries of one very cold night in December to linger and I can’t wait to start the annual spring pruning in our yard. What a relief to be able to cut back those plants to allow for new tender growth to emerge. With the knowledge, training and experience of a horticulturist and an arborist, pruning is easy. Because we do all of our own pruning, we own double edged pruning shears and loppers, several folding hand saws, one pole saw pruner, one gas-powered hedge shears (to cut back ornamental grasses) and a couple of gas-powered chain saws. Stop by home improvement stores or garden centers to see and hold the different tools to see what will work best for you. We keep all of our tools cleaned and sharpened. Pruning can be heavy, repetitive work. Experience has taught me it is worth wearing a good pair of gloves and switching from one tool to another depending on what size branch is being removed. If I don’t take the time to do both things, my hands get tired, my arthritis flairs up and I end up in a rather grumpy mood. For branches less than 1” in diameter, I use the Felco F-2 double-edged pruning shears (two blades that come together in the center for a smooth clean cut). For branches 1”-2” in diameter, I use the Corona forged steel bypass lopper. The long arms give me leverage and the blade sweeps past the lower jaw for a clean cut. Another lopper, known as an anvil lopper, crushes the material that is being cut because the sharp blade hits against a flat surface blade. Compare cutting with scissors versus using a knife against a cutting board. For branches 2”-4” in diameter, a folding pruning saw works great. The one I use is a Corona 10” with a curved saw. Anything larger, I call my husband and he comes in with a chain saw.

I’ve seen a lot of pruning jobs done over the many years as a horticulturist. The most shocking happened when I was an instructor at The Ohio State University. We had arranged for our third-year students to prune an allay of apple trees at a well-known arboretum as a culmination of classes that gave specific instructions of the way to properly prune them, removing cross branches, injured or dead material, suckers and branches within the interior we consider luxury foliage. They were doing a great job so I thought I could quickly arrange for lunch. When I came back, the first few trees only had their main trunks and largest branches left. I thought I was going to be fired for sure. Somehow the students thought “When in doubt, prune it out” was the right method of pruning. Fortunately, for all of us, there was a happy ending. Those trees came back strong with good fruit set and the arboretum was satisfied, and I learned to never leave the inexperienced unattended, in my yard or anyone else’s.

Below are some pruning jobs I’ve seen done that could have used some supervision. Don’t assume your landscape crew is trained. Ask. Remember, if you are going to do it yourself, good pruning takes a combination of proper timing, tools and technique. There are many good county extension websites from state universities that contain in-depth knowledge that offer bulletins that you can print out. They are also available either free of charge or at minimum expense at county extension offices.

• Pruning with unsharpened tools – As mentioned, good sharp pruning tools make clean, smooth cuts which in turn encourage the rapid healing of pruning wounds. The wounds seen in these photos will not heal properly. Notice the uneven, irregular cuts and the torn bark. Damage to the growing tissue found just under the bark will allow for disease and insect problems to occur.

• Reducing plant size of woody ornamentals – Generally, it is recommended that one takes only a third of the growth back over three consecutive years to reduce the size of a hedge that has been allowed to grow too large. It depends on the plant species. When in doubt, look up the proper pruning method and time of pruning. The hedge in this first picture was well over 10’ in height. The homeowner reduced it to just 2’ of bare wood. Because of the aggressiveness of this plant species, this hedge of silverthorn (Elaeagnus pungens) did come back and is now kept at 6 feet in height (Picture 3). Many evergreen species, particular narrow leaf ones like Eastern red cedar, junipers and pine, would not recover from the severity of this pruning.

• Improper pruning technique – When pruning, it is important to prune where the stem and trunk or two branches intersect. In the first picture, the common method of pruning a crape myrtle back to the same location year after year gives the plant a grotesque appearance that I like to call “the angry fist.” When all the branches are removed to the same height which often appears to match the height of the pruner, I call it “crape murder.” In the second and third picture, branches have been cut back to a random length leaving behind a stub.

• Proper pruning technique – In this first picture, the crape myrtle has been pruned back at different points each year, eliminating the “angry fist” look and giving the plant a much more refined and natural appearance. Stem removal was done at a 45 degree angle about ¼” above an existing bud which can be found on the main stem. The second picture shows the proper removal of a large branch. This requires three different cuts: the first cut is an undercut from the bottom of the branch about 6” to 12” out of the trunk and about one third of the way through the branch. The second cut is from the top, about 3” further from the undercut, until the branch falls away. The resulting stub can then be cut back just to the collar of the branch, a wrinkled area on the main trunk where the branch intersects the trunk.

• Properly healed wounds – When pruning is done properly, the growing tissue of the plant will gradually cover the wound site from all edges as seen in the picture on the left. Given enough time it will completely close, leaving only a small knob as a sign of where a limb once was, as illustrated in the picture on the right. Your plant will be happy, and you’ll have the satisfaction of a job well-done.