For the past few weeks we have been addressing the steps to properly diagnosing tree related problems. To refresh, knowing the tree species and what is normal for that specific species are two very key foundational steps. Equipped with that knowledge, we can then define the abnormality. These might be curling foliage, off color foliage, oozing wounds, insects feeding on parts of the tree, as a few examples. Being observant of the site and learning its history is another critical step to be considered. Following that information would be to closely examine the abnormality themselves and will be the focus of our topic this week. Often this is also where misdiagnosis happens. Simply by reaching a hasty conclusion and not looking further, we can easily miss the target issue. This happens often when treating the symptoms, which is not always the issue, but merely signs of stress. Stress is caused from a much larger underlining issue. An example might be small yellowish leaves on a Maple that typically has large leaves, with healthy dark green pigment. A person might diagnosis this as a mineral deficiency and try giving the tree more Nitrogen. However, if a person dug down around the base of the tree to examine the root collar, they might find that the tree has what is called Stem Girdling Roots. These are tree roots growing in a severely twisted form, so much so that they have restricted the flow of water and nutrients up the stem of the tree. The tree is dying from the restricting roots and the small yellowish leaves are symptoms of the restriction.
This issue of not digging deeper, looking further for the underlining problem can easily occur with insects. Sure, many species are prone to specific insect problems but always ask why are the insects there? Trees have many types of defense mechanisms against insects. If insects are present, you might look further for reasons why. What stressors are happening to the tree that are allowing the infestation? A perfect example of this is with Aspen trees. Poplar Willow Borer is currently busy feeding on them. Visible holes in the trunk or limbs and sawdust at the base of the tree can be seen on stressed Aspens with insufficient irrigation in one’s yard. Right down the street in another yard, an Aspen in a mulched bed with plenty of water is fine. The borer is not the issue. Irrigation is. While the attacked Aspen should be treated for the borer, not addressing the irrigation is misdiagnosing the true problem. More next week. As always, for further questions, quotes and consultations, give us a call today!