Drought and trees explained
Texas has already seen extreme heat and very little rain, with the trend predicted to continue.
What can stress a tree?
“Most trees usually die from a combination of different stresses,” said Courtney Blevins, Texas A&M Forest Service urban forester. “One of the biggest stresses we see in Texas is drought. When that happens, stresses build up and secondary pests or diseases can establish in trees.”
Drought-stressed trees So, what happens to
So, what happens to trees during a drought? Ultimately, the lack of water causes trees to photosynthesize less, or make less food, which leads to a lack of nutrients needed to survive.
“Plants generate their own food through photosynthesis, and one of the key components of photosynthesis is water,” said Flocke. “Water is necessary for the chemical reactions that create sugars. It’s also necessary to help move the needed materials around in the tree and, finally, to utilize those materials.”
“The things to look for on your tree are leaves dropping or wilting, small or malformed leaves, yellowing of the leaves and browning tips of the leaves,” said Blevins. “Some species, like junipers, may totally brown out, losing all of their leaves.”
Just because leaves begin to fall from your tree, does not mean the tree is dead. If there is still green underneath, then the tree is not dead. Within a few weeks, it may leaf back out.
If you begin to see signs of stress in your trees and the ground under your trees is extremely dry, it’s time to begin watering. To test the dryness of the soil, you can take a long screwdriver and stick it in the ground. If the screwdriver doesn’t go easily 6 to 8 inches into the soil, it’s time to water.
Water either early in the morning or later in the evening is the best time to water.
An easy tip for watering trees during a drought is to try and mimic what a typical summer looks like for your trees, watering every 10 days to two weeks and knowing that it’s okay to not be on a set schedule – just like normal summer rain.
Avoiding tree stress
“What you’re trying to do is reduce stress to the tree, so pruning, even when you have to, is adding stress because you are wounding the tree,” said Blevins. “If you’re pruning out live branches or live leaf areas of the tree, you’re removing food and the site where the tree’s root growth hormone is developed, affecting root growth and further stressing the tree at a time when it’s already too stressed.”
“Just generally applying fertilizers without knowing if there is a deficiency is a really bad idea,” said Blevins. “If there is not a nutrient deficiency then it’s not going to help anything, and it can actually hurt things and make the tree worse.”
“Trees provide an enormous value to us in our landscape,” said Flocke. “Keeping trees, especially near our homes, can help to reduce overall energy bills, keep us healthier and provide shade for the house.
For additional information on caring for your trees during drought conditions, visit https://tfsweb.tamu.edu/ afterthestorm/Drought/.