By: Anthony C. Arnoldi, Board Certified Master Arborist WI-0102B
There is a strong, stately beauty that only the old and large trees possess, a character and feel that can only come with the years of time necessary to create them. For trees like this to be gracing a property, one must be both lucky and a good steward. Particularly for the trees that were once denizens of a mature forest, and more specifically, the old oaks, beeches, sugar maples, hickories and other slow-growing species that are the real gems. Acquiring and holding onto them can be a challenge.
Their very size and stature usually help to perpetuate myths and misconceptions regarding the care that they need:
- “Their roots are so deep and large that they can fend for themselves in a drought.” Actually, even for the largest oak, its root system is a flat, two-dimensional net. It extends out to over three times the height in all directions, no deeper than two feet deep on average, with most of the feeder roots crowded in the top 6 to 10 inches. All of these roots are subject to heat and drought.
- “Don’t tell me that my tree is looking sick because of construction damage—my house was built 25 years ago!” Trees with large trunks, growing well in a forest environment, have stored a lot of food as reserves. If grade changes, compaction, root cutting or other construction damage badly injure a tree, it may take many years of this tree operating at a deficit to finally make decline symptoms appear. This is because it makes up the difference with energy from its stored food reserves.
- “The construction activity did not hurt my tree because my builder said it has deep roots.” Builders and other contractors usually have little understanding of tree biology, structure and needed measures to preserve trees during construction. It is much easier for them to do their activities without employing these measures, so don’t assume it’s OK.”
- “This tree has been here for 75 years and should keep on going without any help.” The older the tree, the more intolerant of change it is. When they are fortunate enough to stabilize after the initial building and construction activities, they still remain the most likely to falter if a stress like heat, drought, insect attack or storm damage comes. In subdivisions that feature “mature wooded lots,” chain saws can be heard every year, removing dead tops from everdeclining trees or eventually removing them completely.
Indeed, because mature trees have much slowed and reduced growth, they are the most fragile. If the momentum of several years of decline accumulate, it becomes increasingly difficult to reverse the downward spiral. It pays to give these venerable trees needed maintenance periodically before declines have to be dealt with. This care should consider:
- Preventing significant insect or disease attack.
- Removing deadwood and storm damage as it occurs so that health does not deteriorate.
- Removing competition from weedy invasives like buckthorn and honeysuckle.
- Improving the root system—main roots that were once cut or severely damaged cannot be replaced, but the remaining roots must take on the added burden. Encouraging feeder root growth should be maintained with specialty fertilization and root biostimulants. Increasing the performance and efficiency of the root system through inoculation with mycorrhizae has helped many trees ease or stabilize declines.
- Regular, thorough watering during dry conditions.
With this care strategy, many more mature trees could be successfully preserved! With the years of drought wearing on, it makes good sense to make sure you don’t lose the most valuable trees of all. Call your Wachtel Certified Arborist for an analysis of your tree’s condition today.
© Copyright 2005 – Wachtel Tree Science & Service, Inc.