In Texas, we love our trees. Live oak trees spread out wide to make a beautiful shade tree. Pecan trees are the official State Tree of Texas, and we all love their shade and nuts. Who can resist a pecan pie made from fresh pecans in the fall?
Most trees in Texas do well with minimal care, but our trees have faced some challenges over the last few years. Winter Storm Uri was a big stress on trees. We saw broken limbs, limb dieback, cracks in the bark from internal freeze damage, and thin canopies. This year, the drought is an additional stress on our trees. These stresses accumulate over the years and can lead to tree decline and an increase in pest and disease problems.
Trees use water during photosynthesis to create sugars and they use water to move nutrients throughout the tree. When water is not available, the trees photosynthesize less, which means they have less food and nutrients to survive. Without water, trees cannot create sugars and it cannot use the sugars it does have.
Trees will show water stress through their leaves. Many trees will start dropping leaves or wilting. Leaves may turn yellow and have brown tips. These signs do not mean the tree is dead, but they are a sign of stress.
We can help reduce stress on trees during drought conditions by giving supplemental water. There is not a one-size-fits-all formula for how much to water a tree. Consider the type of tree you have, soil conditions, and the age of the tree. A well-established tree in good soil may not need much supplemental water. Monitor your trees to look for signs of stress.
If you do see signs of stress and the ground is extremely dry under the tree, you should consider watering your trees. Water your tree under the crown and extend it a few feet beyond the dripline of the tree. The feeder roots that take up water are not near the trunk, so we want to focus the water closer to the dripline area of the tree.
Soaker hoses, drip irrigation, or a slow trickle from a water hose are the best methods to water trees. Water in the evening, night, or early morning. A deep watering about every 10 to 14 days is better than frequent, light watering. The amount of water you need to use depends on soil conditions and your location. A tree in thin soils will need to be watered more than a tree in heavy clay soils that will hold water.
If you need to provide water to your trees, be sure to check your local watering guidelines. Use an efficient watering method like drip irrigation or a soaker hose when you can to help conserve water.
For more information about lawn and garden topics, contact Kate Whitney, Williamson County Horticulture Extension Agent, at 512-943-3300.