Tree stewards said glossy privets kill off native trees like pecan, elm and live oak

AUSTIN, Texas — Twice a month, Keep Walnut Creek Wild volunteers meet up at the North Austin park just off Parmer Lane to kill as many glossy privet trees as possible.

"Definitely you want to wear gloves because these things are sharp," Stephanie Simmons said describing the tools normally used to perform the task: either the carpet knife or putty scraper.

Simmons striped off a ring of bark, a process called girdling.

In a year, it's expected to kill this tree.

As a tree steward, it's a practice she usually doesn't do.

"This is the only thing that I really will kill," Simmons said.

This isn't an ordinary tree.

KVUE'S Jenni Lee tagged along with the volunteers on President's Day. She asked Simmons, "would you consider the ligustrum, the glossy privets, the zebra mussels of the plant world?"

Simmons quickly responded, "yes! Yes!"

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Glossy privets are an invasive species that are taking over parks and green spaces in Austin.

Simmons was trained under the Tree Folks' Urban Forest Steward program and said they're killing off the native plants.

"They just ruin the ecosystem," she said.

Cliff Tyllick is the organizer of Keep Walnut Creek Wild.

"I've even see them kill junipers and you know if something in Central Texas can kill an ash juniper, it's tough," Tyllick said.

Tyllick likes to call himself the "Grim Reaper to the glossy privet."

His group is working with the City of Austin to reduce the tree's population.

All the green markers are his observations.

"It will kill plants larger than itself, it will choke out everything smaller than itself, it will even come up from seeds so densely, that lots of other plants won't make it past its seedling stage," Tyllick said.

Tyllick's goal now is to teach as many volunteer how to properly girdle or kill glossy privets.

Doing the wrong way, like cutting them at the ground, will only result in regrowth.

Glossy privets are also known as Ligustrum lucidum. Tyllick said the other invasive species taking over Walnut Creek Park is known as the Ligustrum Quihoui.

Tyllick warns of an up and coming invasive called the Chinese pistache that is also dangerous to native plants. It is a common yard tree, like the glossy privets.

He has counted five mature female Chinese pistache in Walnut Creek so far.