Trees might not throw a tantrum or get angry when stressed as we do, but they do have ways of showing that they are stressed. It’s a different kind of stress as well. Sort of like when we are hungry and get irritable. With trees it’s that they are thirsty and or hungry, reaching out for nutrients. They get irritable and in worse cases, through a downright tantrum.
There are two types of symptoms to look for. Acute symptoms appear quite quickly and are easy to spot. This will include wilting and scorching of the leaves. The leaves will have a brown tingle to them around the edge of the leaves. This is an acute water deprivation symptom, easily cured by giving it more water.
Chronic symptoms are more difficult to recognize without a time scale comparison but would include things like the tree growing more slowly and the leaves spotting or even being smaller. Chronic stress may also show because the tree attracts pests and diseases more quickly.
Treatment for Stressed Trees
There are solutions to acute and chronic stress. The roots can be strengthened by adding nutrients through fertilization, mulching, and working the soil. In Colorado, the clay soil conditions can lead to compaction which will deflect water regardless of how many times you water it. A process of tree aeration can help break up soil compaction without damaging the tiny feeder roots which do a lot of the work in water uptake to the tree. Watering along the drip line will encourage the roots to spread out and develop ways to suck up water in more areas of the soil.
Chronic stress may become endemic to the tree so the strategy becomes doing a cost-benefit analysis of keeping the tree alive through spraying to keep pest populations in balance, seasonal fertilization, and maintenance tree pruning.
Some tree species are more vulnerable to stress. Maple, ash, linden, white pine, and flowering dogwoods will frequently become chlorotic with tree leaf color yellowing or browning or stress symptoms may amount to a tree not flowering or turning to fall colors very early in the fall.