Invasive Plant Removal 

PURPOSE

Invasive species are plants that have been introduced to Texas from other regions around the world. They cause problems by crowding out native species and do not provide the same wildlife habitat value. Removing these invasive species allows for a healthier native plant community and a healthier community of other flora and fauna that depend on relationships with native plants.

SAFETY

Use sharp or heavy tools responsibly. Weed wrenches may pinch or injure with their weight. Girdling tools are extremely sharp.

Stay aware of fellow workers to avoid hitting them with trees, limbs, or tools.

Use appropriate clothing and protective gear, including long-sleeved shirt and closed-toed shoes, and gloves and glasses.

Supply first-aid, including gauze, tape, super glue, and other materials for lacerations.

Poison ivy is a common understory plant in many areas of the park. Avoid coming in contact with any part of this plant. Wear long sleeves and pants to avoid skin contact.

MATERIALS

Tools needed:

  • Gloves and eye protection

  • Weed wrench or Lawn Jaws

  • Utility knife or linoleum knife

  • 2-3” stiff putty scraper or similar

  • Coarse plastic scrub pads

  • Spray bottle with soapy water

  • 70% rubbing alcohol

METHODS: INVASIVE WOODY SPECIES

Includes glossy privet, Chinaberry, Chinese pistache, Nandina, photinia, golden raintree, and Chinese tallowtree

If focusing on a large area of 75% or greater invasive species cover, it is recommended to remove no more than 1/3 of the invasive trees during one season if using mechanical removal. Girdling is a preferrable method for areas like these.

MECHANICAL REMOVAL: WEED WRENCH

1.For saplings 2” or less diameter (measured at the base of the trunk), uproot using a Weed Wrench or other mechanical device.

2. Provide for erosion control or restoration plantings as needed.

3. Leave as much of the pulled material as possible on site in low-use woodlands, taking care to remove any seed material, and leaving roots without soil contact.

4. Plan on removing seeds or fruit from the site.

5. Ensure woody material is broken down into shorter lengths and lays flat on the ground surface so that it readily decomposes. Do not leave large piles of brush or logs in natural areas. Reference Trail Brushing sheet for ways to use brush to close informal trails.

GIRDLING

For trees 2” or greater diameter (measured at the base of the trunk).

  1. Peel Bark (and Phloem)

    • Use a flat-edged scraping tool (e.g., putty knife, 5-in-1 tool) to peel away the bark and phloem between the two cuts.

    • The bark should separate relatively easily from the sapwood. 

  2. Scrape Away Remaining Bark Layers

    • Using the same scraping tool, remove the remaining phloem (the wet, toothpick-like fibers between the bark and sapwood).

    • Stop when you reach the smooth, lighter-colored sapwood.

  3. Remove Remaining Phloem and Kill Phloem Cells

  • Use a coarse plastic scrub pad and soapy water to scrub the exposed sapwood until all remaining fibrous material is gone.

  • Scrub again with 70% rubbing alcohol to kill any exposed phloem cells.

NOTES

For mechanical removal of Chinese pistache, loosen soil at base of plant to reduce the risk of the trunk snapping at the base.

For girdling of Chinaberry and Chinese pistache, plan to follow up every 3 months to remove or girdle new sprouts from the trunk.

Plan for re-seeding or planting in the areas where significant amounts of invasive plants are removed or soil is disturbed. Reference Restoration Plantings sheet for more information.

For video instructions on girdling ligustrum, refer to “Demonstration of Invasive Tree Girdling with Cliff Tyllick”, available on YouTube: