Drought bringing Texas-Sized Thirst to Trees, Plants,
Turf, Statewide,
by Paul Schattenberg

SAN ANTONIO - While much of the attention relating to the statewide drought has been focused on it effect on crops and livestock, the effect of the drought on trees, plants and turf grass should not be overlooked, said a Texas Cooperative Extension expert.

"We've had an unusually dry winter and most parts of the state are way behind in their average rainfall," said Jerry Parsons, Extension horticulturist and radio personality. "As a result, a lot of people are going to have serious plant and turf losses if they don 't do something pretty soon to address the problem."

The poor condition of many trees, plants and lawns across the state has much more to do with the lack of rain than the fact that it is winter, he said.

"A lot of what people are seeing around the state in the way of wilted, dried-up looking trees and plants, sparse leaves and dry and 'crispy' lawn turf is because they're 'thirsty,' not because of colder winter temperatures," he said. "We've had a relatively mild winter with few hard freezes in the state this year. So while many people may mistake the signs of 'stress' on trees, plants and turf for their natural response to winter conditions, such as going dormant, this
typically isn't the case this year."

A check with the El Paso horticulturist reveals this recommendation for that desert climate:

"In general, if the landscape is established, mostly deciduous and dormant (even turf), a good thorough soaking (1- inch) once per month will be enough. If there are evergreens in the landscape, once a month is fine for most trees and twice a month will do just fine for most
shrubs and smaller plants. There are not many plants in our landscapes
that would require more water than this in the winter. At the extreme outset, for established, non-native/non-adapted plants, I would recommend once per week, but in a drought situation, I think that twice per month would keep most things alive, although maybe not too happy.
Not many people have bedding plants in their landscapes out here, but if they do, I would recommend once or twice a week for those areas."

Dr. Jim McAfee, Texas A&M Turfgrass Specialist in Dallas writes:
"I have always recommended winter irrigation of landscapes, particularly lawns if adequate rainfall does not occur in a 30 to 40 day period. The number one loss for turfgrass in the winter time is dessication, not low temperature kill. Also, if a soil is dry when a freeze occurs, then the amount of injury from the freezing temperatures will be greater."

"I can relate back to 1988-89 when we had our last real hard winter in Dallas-Fort Worth area. I was with ChemLawn at that time and we lost 3,500 customers because their St. Augustinegrass lawns died from the freeze. However, we had a lot of customers that did not loose any St. Augustinegrass in that same winter. When talking to customers, the most common denominator for homeowners who did not loose their St. Augustinegrass lawns was that they watered in the winter months."

"I am very concerned about this year, because our soils are so dry and a lot of people have not been watering their lawns. Time will tell, but I expect to see some damage in the Dallas-Fort Worth area."

Commenting on the fact that the EvapoTranspiration Report or as SAWS calls it, the SIP (Seasonal Irrigation Program) gives a recommendation to water St. Augustine in the sun in the winter drought but don't water St. Augustine in the shade in the winter drought IS BACKWARDS!!!!!!!! because the trees' rootsystems are robbing more water from a turfgrass than the sunny, cool weather is causing transpiration from the turf because they are trying to equate summer water loss to winter drought water loss, i.e., to prove the point, look at the images at:

http://www.plantanswers.com/drought_images/22.jpg

http://www.plantanswers.com/drought_images/24.jpg

and

http://www.plantanswers.com/drought_images/23.jpg

Dr. McAfee totally agreed about the watering-grass-under-trees issue.
"How someone can not understand that a plant, such as a green and growing tree, is taking more water out of the soil than dormant turfgrass is beyond me. I have always found it scary that these type of people are the ones writing regulations."

Even hearty and drought-tolerant trees and plants are developing signs of severe drought stress, said David Rodriguez, Extension horticulturist for Bexar County.

"Hollies, Ligustrum and live oak are all showing stress in this area, and we're seeing a lot of dead or dying magnolias as well," he said. "Many older, more well-established trees and plants are showing sparse foliage and blooms, brown branches and shriveled wood."

Brown and "crispy" lawns are also a typical sight throughout the state, he added.

"Many people in the state are uncertain about what to do about watering their lawns," said Roger Havlak, Extension turf grass program specialist. "If you're in a area where there has been no significant rain for two to three weeks or more, it's probably time to water."

The best way to determine whether a lawn needs watering is to use a spade or shovel and probe about 6 to 8 inches below the soil surface, Havlak said.

"If there's no moisture or only a few inches of moisture at the top, you should consider supplemental watering," he said. "Water needs to penetrate far enough down to provide nutrition to the root system to be of any significant benefit."

Some people in more drought-stricken areas of the state may assume their turf grass is beyond help and decide to dig it up and make room for new sod, Havlak added.

"It's really too early to be thinking about doing anything that drastic at this point," he said. "With some supplemental watering and additional care, even turf grass in very poor condition may be saved. It's best to wait until late March or early April to decide if your turf looks as if it will ultimately survive."

The drought and accompanying stress on trees and plants has also made them more susceptible to certain natural enemies, added Molly Keck, Extension entomologist for Bexar County.

"Wood-boring beetles are attracted to stressed trees and shrubs more so than healthy ones," Keck said. "We should be keeping a close eye on them for signs of them, such as holes in trunks and branches or finding adult insects or larvae under the bark."

Damage caused by chewing and sucking insects probably will be more noticeable than in the past, she said. This is partly because these insects are more attracted to stressed and weakened trees and plants, and partly because these unhealthy trees and plants are not as able to repair themselves.

The best way to prevent further stress damage and have healthier, more attractive trees, plant and lawns is to water and maintain them properly, said Rodriguez.

"When you water your lawn, you have to remember to water your trees and plants at the same time," he said. "You should apply a minimum of one inch of 'top dressing' to your lawn at least two times a year, preferably in late February and mid-October.

In times of serious drought, trees, shrubs and grass should receive an inch of supplemental water per week, he added.

"Soil holds enough water to nourish trees, plants and turf grass for about two to three weeks," he said. "In addition to watering at least every three weeks during growing season, you should water less
often and for longer periods of time to ensure adequate penetration."

Some additional attention to watering and horticultural maintenance now can save homeowners and other landholders a lot of time, trouble and expense in the spring, he said.

"It will add to your water bill and there is usually time and expense associated with mulching and composting," Rodriguez said. "But
when you consider what it may cost for new trees or plants - or to put
new sod on your lawn - it 's well worth it.."

Additional information on winter watering during drought can be found at:

http://www.plantanswers.com/drought_watering.htm

and

http://bexar-tx.tamu.edu/HomeHort/F1Column/2006%20Articles/FEB26.htm

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