Texas-Sized Thirst to Trees, Plants,
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 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
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
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:
Dr. McAfee totally agreed about the watering-grass-under-trees
"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
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
when you consider what it may cost for new trees or plants - or
new sod on your lawn - it 's well worth it.."
Additional information on winter watering during drought can
be found at: