Drought Stress in Trees

Young or newly planted trees are most susceptible to heat or drought as they have small juvenile root systems and cannot reach available water deep in the soil. It is common to see symptoms of stress in trees 4 years old and younger, although mature trees can suffer stress as well. Symptoms vary from species to species and severity of stress, but common indicators include, yellowing or browned leaves, wilted branches and leaves, leaf drop or premature fall color display.

How to prevent heat stress:

Because we can’t adjust the thermostat or turn on the rain, the only way to protect your tree from heat or drought stress is adequate watering. All juvenile trees should be watered regularly when adequate rain is not received. A young tree requires about 2.5 gallons of water per caliper* inch and should be watered slowly to allow moisture to reach deep into the soil.

If you notice drought stress, do not be tempted into overwatering as your tree can easily drown if applied water is increased drastically. Continue watering at a rate of 2.5 gallons per caliper* inch, however, watering frequency can be increased slightly. Instead of watering weekly, you should increase to water every 4-5 days when the weather is exceptionally hot. It is important to continue watering regularly until the ground freezes as the tree will acclimate to applied water and suffer if discontinued.

If your tree is stressed, wait until spring to count your loses. Sometimes trees can lose all their leaves due to stress and still come back the following spring with minimal damage. However, some trees are not so lucky and will not make it through drought stress.

*caliper inch = diameter of tree trunk