Tree News

Dallas and North Texas counties under quarantine to save beautiful ash tree

Dallas and North Texas counties under quarantine to save beautiful ash

ash tree
Ash trees are one of the nicest trees in Dallas and in the U.S. YouTube

UPDATE 6/6/2022: The City of Dallas has been notified by Texas A&M Forest Service (TFS) of the confirmed presence of the Emerald Ash Borer (EAB) inside the city limits and western Dallas County. The EAB is a non-native, wood-boring insect destructive to ash trees.

Dallas County now joins Parker and Tarrant Counties in a quarantine status, mandated by the Texas Department of Agriculture, that prohibits moving ash wood, wood waste, and hardwood firewood products from within Dallas County to other non-quarantined counties.

As part of an action plan, City staff will:

  • assess ash trees on public property
  • treat significant ash (24-inch or larger in diameter and in good condition, large groves of ash, etc.)
  • and remove infected or damaged trees that pose safety issues

According to TFS, urban tree canopy inventories estimate that ash trees comprise approximately 5% of the Dallas/Fort Worth urban forest.


An invasive beetle that kills off ash trees has been discovered in Dallas County, and tree experts are calling for immediate action.

The beetle is the Emerald Ash Borer (EAB), a wood-boring beetle that targets all ash trees. According to a release from Texas Trees Foundation, the beetle poses a substantial threat to Dallas' urban forest, on both public and private land:

  • EAB kills unprotected ash trees within 2-3 years of infestation and can eliminate entire stands of ash trees within 10 years.

The urgency has escalated because, on May 19, the Texas A&M Forest Service confirmed the presence of EAB in Dallas County.

Evil beetle
Native to Asia, the emerald ash borer beetle was unknown in North America until its discovery in southeast Michigan in 2002. Since then, it has spread to 35 states including Texas, where it was first detected in Harrison County in Northeast Texas in 2016. It's since been detected in Bowie, Cass, Dallas, Denton, Marion, Parker and Tarrant counties.

EAB have a distinctive iridescent green and copper color, and a bullet-shaped body typical of buprestid beetles. There's a photo here. Don't be fooled by their cool colors, they're evil.

The beetle has gone on to kill millions of ash trees across much of the country. Ash trees are widespread in the United States and all 16 native ash species are susceptible to attack.

The beautiful ash
Ash trees are amazing. They're a perennial, so they grow new leaves every spring and shed their leaves every fall. The leaves are pointy and oblong, and turn a beautiful yellow-gold-red in the fall.

The bark has little diamond-shaped grooves, and the trees grow into beautiful shapes.

There are only good things to say about ash trees.

EAB symptoms
Ash trees beset by the EAB often have few or no external symptoms of infestation, but may include any or all of the following:

  • dead branches near the top of a tree
  • leafy shoots sprouting from the trunk
  • bark splits exposing larval galleries
  • extensive woodpecker activity
  • D‐shaped exit holes

The EAB is a considered a significant threat to urban, suburban, and rural forests as it kills both stressed and healthy ash trees. It's very aggressive, and ash trees may die within two or three years after they become infested.

Texas Trees Foundation's 2015 State of the Dallas Urban Forest Report found that at least 13.1 percent of all trees in the city are ash, or approximately 2 million ash trees across Dallas.

In the Great Trinity Forest, 23 percent of the tree population is at risk.

The Texas Trees Foundation is calling for the city of Dallas to take proactive steps, starting with an assessment of the condition and location of the ash trees on public property, including the Trinity Forest.

Private homeowners/landowners are also crucial to effectively combating EAB.

Keeping the ash trees alive
The most effective mitigation strategy is to slow the spread using a SLAM approach (SLow Ash Mortality). This strategy includes:

  • monitoring ash trees for EAB
  • injecting ash trees with systemic insecticide
  • removing low-quality ash trees
  • following quarantine regulations
  • replacing ash trees with different tree species to diversify the urban forest

Texas Trees Foundation CEO/president Janette Monear is urging the city to immediately conduct a tree inventory of publicly owned lands, to identify the healthiest ash trees for monitoring and to apply insecticide.

The hope is that this approach will slow the spread of EAB by reducing population size of the insect, preserving valuable ash trees of differing age and size, protecting Dallas tree canopy cover, and minimizing public costs overtime.

Texas Trees Foundation's urban forestry manager Rachel McGregor warns that EAB poses "a serious threat to Dallas’s urban forest," especially the Great Trinity Forest where most of the city's ash trees are found.

"We can mitigate this threat through a strategic, integrated, research-based approach, which is more financially and environmentally effective then just removing all the ash trees or letting them die," McGregor says.

Things you can do
Residents who have ash trees are advised to take the following steps:

  • Confirm/identify if they have ash trees on their property
  • Engage an ISA Certified Arborist to assess their ash tree and help them decide a course of action
  • If systemic injection treatment is desirable, hire a certified arborist with a current TDA pesticide applicators license. The most effective treatment is with a systemic insecticide injection of Emamectin Benzoate (this product is a restricted use pesticide)
  • Monitor trees for EAB – if the tree has been systemically injected with Emamectin Benzoate, the treatment will last 2-3 years
  • If ash tree removal is necessary, comply with Texas Department of Agriculture's EAB quarantine regulations

And to report an emerald ash borer, call 1-866-322-4512.