Water, water, water! Water is one of the most important things you can give your landscape- especially in the Summer months! In fact, according to the University of Arizona College of Agriculture, plants use 3-5 times as much water during Summer as they do during Winter months. To ensure you are efficiently watering your trees as temperatures rise, you should be aware of how water absorption works, the amount of water you should be giving your tree, and the best techniques for administering that water.
Water Absorption in Trees
While many people may think the best place to water a tree is near the trunk, the most active water absorption area is actually located at the drip line and beyond. The drip line is the area that can be found under the ends of the tree’s canopy and is also known as the Critical Root Zone. This is where trees shed rain water and it works as a storage tank for the plant to draw nutrients and water from when needed. While that may seem far from the base of the tree, most tree roots actually spread 1 to 4 times as wide as the canopy!
Evapotranspiration is a process where trees can move water through their roots, branches, trunks, and leaves- ensuring that all parts of the tree receive water. In the Summer, when the temperatures are high and the ground is dry, trees find water to be a more limited resource and have to choose where to delegate that water- with the leaves typically being the ones that suffer the drought. Common signs that a tree is not absorbing enough water is yellowing/browning of leaves or complete leaf drop-off.
Amount of Water to Give Trees in the Summer
The amount of time that you should be watering your trees and plants depends on a variety of factors including the weather, soil status, size of tree/plant, and type of irrigation system. A good rule of thumb is to water the root zone at the indicated depth (based on size of the tree) and not any deeper than that so as to cause wasted water. If your soil is shallow or compacted, be sure to water more often but for less time and water younger plants more often than you would older plants to prevent wilting in the Summer months.
How to Water Your Trees Efficiently
There are multiple different systems for irrigating your trees and each has its own set of pros and cons of use. Drip Systems, Bubblers, Soaker Hoses, and Sprinklers are all common ways to ensure your landscape is getting the irrigation it needs. For more information on the differences in these systems, click here.
To make sure you are watering in a way that will not harm the tree or waste water be sure to avoid spraying water on leaves (salts in the water can harm the leaves), water your tree separately than your turf if your tree is planted in a turf area, control weeds near your trees and plants, and expand the watering area as the tree grows.