Dallas tree group says water your trees, not your grass during drought

Texas Trees Foundation says save the trees, not your lawn, during the current drought.

Trees along a street in Dallas, Texas

Texas Trees Foundation says save the trees, not your lawn, during the current drought.

North Texas is experiencing a drought, so the Texas Trees Foundation urges local residents and property managers to prioritize trees over lawns and other landscaping plants when watering in order to save both natural resources and the valuable tree canopy over the city.

The National Integrated Drought Information System indicates that moderate to severe drought conditions have overtaken Dallas County, and extreme drought has gripped the counties to the south. The lack of moisture in the soil and high temperatures are causing greater stress in trees throughout the North Texas region, which makes the trees vulnerable to a variety of threats and puts them at a greater risk of dying out.

Trees along a street in Dallas, Texas
A tree canopy over a street in a Dallas neighborhood helps to reduce the urban heat island effects. Photo courtesy of the Texas Trees Foundation.

“Supplemental watering to trees, during our Texas summers, is vital in reducing tree stress,” says Rachel McGregor, urban forestry manager for T.T.F. “Our urban trees already live in a stressful environment but with added heat and drought stress, trees will be vulnerable to secondary pest and pathogens. When trees die, it’s typically a combination of things that contributed to its demise, keeping your tree properly watered can help tree vitality and response to these secondary problems.”

Water is a limited resource in North Texas, so homeowners and property managers must decide whether they should keep watering their lawns as usual or focus on saving their trees.

McGregor opts for the trees, saying a turfgrass lawn left unwatered will naturally go dormant for the season and turn brown but can be revived once rainfall returns. Also, if reseeding or re-sodding grass becomes necessary, a lawn can often be reestablished in a single season whereas a large tree cannot. Therefore during a drought, she says local residents and property managers should opt to save trees, not turf.

In Dallas, a mandatory watering schedule is effective. No watering is allowed on Mondays, Tuesdays or Fridays. And from April 1-October 31, watering is prohibited between 10 a.m. and 6 p.m. on all days of the week. Watering by means of an automatic irrigation system or a hose-end sprinkler must follow the schedule based on a location’s address. However, drip irrigation, soaker hoses and hand watering are allowed on any day and at any time.

McGregor says that to water trees optimally, water should slowly flow from a bubbler attachment or multiple drip emitters, or be left to trickle from the end of a garden hose, in an area that extends from the dripline of the tree to about half the distance toward the trunk. The dripline is the furthest point that a limb reaches out from the center of the tree.

Watering a large, established tree right up against the trunk is not advised as tree roots reach out about as far underground as the limbs climb overhead, and the best place for a tree to uptake water is near the ends of its roots.

The simplest method of watering is to turn a garden hose on a slow trickle and leave it in different zones within the dripline until a screwdriver can be inserted easily into the soil. Deep watering encourages deep roots, and deep roots are best for the tree. During a drought, trees may need to be watered every couple of weeks.

Additionally, the organization offers tips on just how to optimally water trees:

  • The best time for summer watering is in the morning or evening from 7 p.m. to 8 a.m.
  • Avoid watering during the hottest part of the day, 10 a.m. – 6 p.m. to reduce water loss from evaporation.
  • Remove grass and excess plant competition from around any tree to decrease water stress.
  • Use mulch to conserve water and prevent weed competition.
  • Do not fertilize trees during the summer.
  • Do not prune trees during the summer unless dead limbs and branches must be removed.

McGregor says the value of trees warrants an investment in helping them to endure a drought. Aside the visual appeal of greenery in a landscape, trees shield the city from direct sunlight and therefore help to tamp down the urban heat-island effect, which is a general warming of an urban area as buildings and pavement intensify heat throughout the day and then release stored heat during the night.

“Trees provide an enormous asset to our landscape by reducing heating and cooling cost in our homes, cleaning the air we breathe, increasing our mental and physical health, decreasing storm water runoff, and many other benefits,” McGregor says.