Across state, drought-stressed trees need watering

(08/14/23) BATON ROUGE — After weeks of extreme heat and little rain, the landscape is looking parched.

While gardens and lawns are the first to show evidence of a water shortage, trees are also in need of care.

“Everything in the ground right now is water stressed,” said Hallie Dozier, an urban forestry specialist with the LSU AgCenter.

Most of the state has been rated abnormally dry or in moderate drought, according to the U.S. Drought Monitor, a service of the University of Nebraska-Lincoln, the U.S. Department of Agriculture and the National Oceanic and Atmospheric Administration. Some areas of central and south Louisiana are experiencing moderate to severe levels of drought.

Experts at the AgCenter have received reports of bark cracking and parts of tree canopies dying back. Periods of dryness cause many typical strains to become “enhanced,” Dozier said, as trees become more vulnerable to disease and insects, but also to limb breakage and wind damage.

When trees have not received significant rainfall in two weeks, Dozier recommends the following steps:

  • Place a soaker hose in the root zone of the tree — the area starting from about 2 feet from the base of the tree to the canopy line.
  • Set the hose to a slow drip and allow it to run for 24 to 72 hours.
  • If water begins to run off the surface, turn down the volume.
  • If water continues to run off the surface, check for saturation.

To check if the soil is saturated to the proper depth of 6 to 8 inches, stick a screwdriver into the ground up to the handle. If the screwdriver shaft is wet and dirty, the soil is saturated deeply enough to benefit the tree.

If you do not own a soaker hose, a regular water hose can work, but it needs more attention. Leave a regular water hose on a slow drip and move it to different areas of the root system every six to eight hours.

Smaller and younger trees need more frequent watering than well-established trees, Dozier said, but all trees need help when hot, dry conditions linger.

“The big trees are the ones that are valuable to us as homeowners,” she said. “All they do for us in terms of cycling water, cleaning the air, holding the soil and providing wildlife food and nesting sites and shade is important. That's a big one for us — shade. Big trees are the ones that really give us a lot of bang for the buck. So, they really do need to be protected.”

Some deciduous trees — those that lose their leaves all at once at the end of the growing season — may lose their leaves early this year because of prolonged dry conditions. Some homeowners may worry that their trees are dying, but this early dormancy is an action of last resort by a water-stressed tree, Dozier said.

“They're just kind of in a resting state,” Dozier said. “That is a strategy that plants will take when water becomes very difficult to get because they need water to support a canopy.”

Extremely taxed trees may begin to look dead. Dozier encourages landowners to wait before cutting or trimming them.

“Take up a watering regime to ensure the tree is going to rehydrate then see what happens in the spring,” she said. “In the spring, if you don't get leaf-out or you only get partial leaf-out, then you can make decisions about either removing the tree as a whole or doing selective pruning to remove dead tissue.”

Occasionally, less scrupulous tree services may tell homeowners these dormant trees are dying and dangerous and must be cut soon, Dozier said. She advises Louisianians to only use arborists licensed by the Louisiana Department of Agriculture and Forestry. A list of licensed arborists can be found at the LDAF website.

Watering trees during times of drought and abnormally dry conditions will not bring them back to ideal health, Dozier said.

“What we're going to do is reduce that drought stress on the trees and maybe give them just enough that they can get through until the rain starts again,” she said. “You can't afford to put out hundreds and hundreds of gallons of water every day to replenish the soil. But, hopefully, you can help supplement it enough that the tree can get by.”

8/14/2023 5:25:07 PM
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