What Lurks Below… Strikes!
Written by: Tony Arnoldi, Board Certified Master Arborist WI-0102B
In my previous article on this subject (spring issue), I pointed out what the consequences for trees and shrubs were, having gone through the very dry 2021 growing season. They were then punished further, by going through the extremely dry winter. By the end of spring, it could be seen that many evergreens were injured, and even many deciduous trees had extra dieback or large sections of weak or dead branches developing.
Since that time, it has become obvious that the extent of the damage done was greater and involved far more trees and shrubs than originally thought. On many deciduous trees, leaf-out was expected to continue to come in until canopies reach their normal densities. But for a lot of Crabapples, Pears, Hawthorns, Japanese maples, and others, it simply did not happen. Furthermore, trees that have been under treatment for many years – for things like needlecast and tip blight, chlorosis management, borer damage recovery, and root-building to replace roots lost to root rot fungi – “took a step back.” Extra needles were lost, extra dead tips developed, and more dieback than normal resulted from scale, mealybug, aphid, and other insect outbreaks that were controlled last year. It is very frustrating to see a good, consistent response to treatment be interrupted by a year of backsliding. Trees with pre-existing conditions were affected the most.
On the positive side, this year has seen much better precipitation although not without periods of drought and heat stress itself. The monster of bone-dry subsoil is still very much alive, ready to attack the root systems of plants that become vulnerable.
The way to conquer it is to be consistent with the care program that has been prescribed for your trees. Growth can and is being made up when attention is paid to the good cultural care clients need to provide coupled with precise, targeted treatments against known disease or insect stressors.
Watch for the inevitable change in soil conditions. Being ready to provide water is certainly the first step. Recognizing the relative drought tolerance of your different trees can help you triage the list and provide the first and most frequent waterings to the most vulnerable species. Recognizing the driest sites on your property can help prioritize also. Measures to conserve water that is received both from rain and the sprinkler are important. These include watering in the evening to reduce losses from evaporation, and mulching trees. Creating mulch circles or adding mulch to the proper thickness/depth in existing beds will help a lot.
In fall, measures to help trees replace or build the number of feeder roots will compensate for this stress and damage. These measures include Fall Fertilization with Root Biostimulants, Root Biostimulants with Systemic Fungicide, Compost Tea, and Mycorrhizal root Inoculation — all have their place. Helping in a greater capacity could utilize our Root Enhancement Service that can convert an area of root-hostile turf environment into an oasis for root growth and function.
Call your Wachtel Tree Science Certified Arborist for an assessment of the tree and site conditions and determine the best strategy for your landscape.