As the old song goes, “Let it Rain, Let it Rain, Let it Rain”. For certain, Illinois needs the rain. The entire State is currently experiencing some form of drought, with the most severe conditions affecting the southern part of Illinois.
People aren’t the only ones feeling the effect of the drought. Trees and shrubs also become stressed by dry conditions, especially when temperatures climb higher and higher. Signs that a tree or shrub are dry can vary by species. For example, River Birches and Tulip trees will lose leaves to cut down on water loss. Oak trees develop a thick waxy coat on their leaves and needled evergreen trees and shrubs have protective resins that prevent the plant from drying out quickly.
Established trees and shrubs have an extensive root system that helps support the plant during periods of varying weather conditions. Although, a tree may take 5-10 years to become fully established. In addition, it’s the fine fibrous (feeder) roots that are responsible for taking in water for the tree. These are located just 12-15 inches under the soil, at the outermost branch canopy. This is also the layer of soil that dries out the quickest during hot, dry weather conditions.
It’s important to properly water trees and shrubs in a manner that uses the water most effectively. Because water is mainly absorbed away from the tree trunk, it’s essential to guarantee the outer tree canopy area is receiving water. Also, trees and shrubs prefer deep watering, rather than small, frequent amounts of water. There are a number of ways this can be accomplished. While sprinklers can be used, it should run slowly and may need to be on for 90-120 minutes to provide the correct amount of water. The goal is to give the tree or shrub an average of 1 inch of water per week. Water requirements for a tree or shrub can vary. For example, water loving trees, such as the River Birch may need at least 3 inches of water per week when summer temperatures soar.
If in doubt about the water requirements for your trees and shrubs, contact the Plant Health Care Department at KTS to discuss your specific situation. We can recommend other watering methods that may be more beneficial.