SAN ANTONIO In addition to its impact on agriculture, the extended drought has caused serious problems with lawns and landscapes in South Central Texas and beyond, said a Texas Cooperative Extension expert in San Antonio.
“We’ve had 17 months of drought conditions, and thousands of lawns throughout the area are looking terrible,” said David Rodriguez, Extension horticulturist for Bexar County. “And we’ve recently been getting lots of calls about plants, even hardy native plants, that are dead or dying from drought stress.”
Red oak, yaupon holly, Burford holly, wax-leaf ligustrums and Southern magnolias are among those affected, Rodriguez said.
“Mostly we’re seeing problems in younger, less-established trees and plants, but even older specimens are in distress,” he said. “In addition, people are worried because their grass is dying or showing extensive discoloration.”
While some of the difficulties with turfgrass, especially St. Augustine and bermudagrass, have been the result of chinch bugs or grubs, the vast majority are related to drought stress, he said. But applying compost can help retain a lawn’s moisture.
“We normally recommend that people feather a half-inch of compost top dressing onto their lawns around the middle of October or April,” Rodriguez said. “But with the current drought situation, it would be a good idea to do it now. This will help hold in the moisture and also help protect the grass from the heat. Over time it will help build soil depth too.”
There may be some initial yellowing of the grass 10-14 days after composting due to heat and decomposition of organic matter, he said, but this is temporary and the grass will begin to green up soon after.
“Of course, the major reasons we’re seeing a yellowing of turfgrass are drought stress and a temporary iron deficiency in the lawns,” he said. “If it’s an iron deficiency, you can green up your lawn by applying a liquid chelated iron spray.”
Watering sufficiently and efficiently is another way to save lawns during drought, he added.
“People in this area should be watering about an inch per week,” he said. “But it’s very important to water in such a way as to get adequate penetration. And if you have a lot of clay in your soil, you need to aerate or soften it to allow more moisture to get in.”
Proper watering is particularly important during water rationing, he said. “You can’t afford to miss your window of opportunity for watering,” he said. “And you need to water adequately to ensure there’s enough moisture to last until the next watering day.”
Don’t assume trees, plants and shrubs are getting adequate water when watering the lawn, Rodriguez said.
“They will likely need more water than what they get from your sprinklers,” he said. “Placing a soaker hose on the ground beneath the leaf canopy drip line is a good way to irrigate large trees, shrubs and foundation plants.”
Applying 2-4 inches of a hardwood mulch around tree beds also will help, Rodriguez said.
“Mulching is the key to containing moisture,” he said. “You need to irrigate, then mulch, then irrigate again. An organic mulch is one of the best types to use.”
This would also be a good time to consider replacing dead or dying plants, trees or shrubs with more drought-resistant substitutes, he said.
“People may want to rethink their landscaping and make Xeriscaping choices,” he said. “Well-adapted native plants, trees and shrubs have a much better chance for success during drought.”
More information on drought-tolerant plants for South and Central Texas can be found at http://bexar-tx.tamu.edu/HomeHort/F4Best/nLowWaterPlants.htm .
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