By: Anthony Arnoldi, Certified Arborist
Everyone loves to see majestic evergreens in winter contrasting nicely with the snow adorning them. They help form Christmas card scenes and give shelter for wildlife. In summer, too, they add richness of greens and break up the texture of leafy patterns. They usually occupy very prominent places in our landscapes because they look good year ’round. Many people give preference to keeping the evergreens healthy in their yards.
Evergreens have one big disadvantage, however. They are no match for leafy foliage. Whenever leafy (deciduous) foliage completely overtops them, blocking vital light, they respond by losing needles and becoming thin. When leaves are growing up to their side, light gets diminished and they lose needles on that side, eventually becoming misshapen. As growth continues and the resulting shade gets heavier over the years, the needle loss continues until whole branches are bare. If this happens on all sides, the whole evergreen could die. Pines, spruces, firs, arborvitaes and junipers all react this way.
I am often asked to evaluate the pruning needs of all the trees on a property. I always will ask what priority is placed on the evergreens if shading is imminent or beginning to occur. If it is, I will prescribe the directional pruning of deciduous trees away from the evergreens to achieve spacing between their crowns. In this way, sunlight can again reach all sides of the evergreens and stop or prevent needle loss. Needle replacement can even happen if the damage was not too prolonged or extensive. Some difficult decisions may need to be made in removing either the evergreen or the deciduous tree if there is an unresolvable conflict.
Most people have no idea this battle is going on. Even most landscapers and landscape architects tend to overplant and/or place trees too close together—starting this battle only a few years after installation. Many fungal diseases of evergreens find that the stressed needles and the darker, moister environment works greatly in their favor, and controlling these diseases under these circumstances can be hampered. Proper pruning can actually aid disease control and is part of a plant health care program.
Shrubs, too, can be overlooked. When they are initially planted to surround evergreens, such as spruce, all looks great. However, over time, the shrubs grow up to the sides of the spruces (and vice versa), causing the evergreen branches behind these shrubs to quickly die. Pruning or removing shrubs before they cause evergreen branch death is important.
Fortunately, through proper decision-making and careful pruning, many of these conflicts can be resolved or managed, allowing for the co-existence of both deciduous and evergreen trees. Along with pruning to create spacing between them, sometimes thinning and/or raising to allow light through to the evergreens works well. Similarly, growth regulator treatments can sometimes be used to increase light to evergreens by regulating (or reducing) growth of deciduous trees. This can also help to extend the time that the pruning will aid in increased light, resulting in cost savings.
Clients are always grateful to know about this problem and how it can be resolved. It definitely is factored into the pruning prioritizations that are given. Call your Wachtel Certified Arborist today to see how your evergreens can be preserved.
© Copyright 2002 – Wachtel Tree Science & Service, Inc.