On a bright, cool Saturday morning, October 22, a small group of folks joined Aaron Haynes, Land Steward at Wild Basin Creative Research Center, to remove invasive plant species from the creek area in Wild Basin. The plants of concern on this day were nandina (Nandina domestica), Japanese ligustrum (Ligustrum japonicum), and Chinese ligustrum (Ligustrum lucidum), and the tools of choice were an EZ Ject lance, a weed wrench, a hand saw, liquid poison, and elbow grease.
Nandina and both kinds of ligustrum are extremely invasive in central Texas, especially in riparian areas. These, like many other invasive species, have been imported and cultivated by humans, have very effective methods of reproduction, and are very hardy and well-adapted. Unfortunately nandina and ligustrum are still prominent in Central Texas landscapes, which makes them even more difficult to control in our wild, riparian areas.
Nandina is a broadleaf evergreen shrub that bears showy red fruit. Birds spread the seed, and new plants can grow from the strong, extensive root system. Japanese ligustrum can become a tree, has showy white flower heads, and produces black berries that birds love, especially cedar wax wings. The leaves are bright green with a smooth edge and are oppositely arranged on the stem. Chinese ligustrum also has an opposite leaf arrangement but much smaller leaves and grows as a shrub rather than a tree. It is often difficult to distinguish Chinese ligustrum from the native yaupon (Ilex vomitoria) since the leaves of these two species have the same size, shape, and color. The easiest way to know the difference is to look at the leaf margins and the arrangement of the leaves on the stem. The leaf margin of ligustrum is smooth, and the leaf margin of yaupon is usually slightly serrated. The most telling factor, however, is that yaupon leaves are alternate, not opposite, on the stem.
Although ligustrum seedlings can often be uprooted by hand, the larger plants need heftier tools than a firm grip and a strong back. The EZ Ject is a large (expensive) lance that injects a pellet of poison into the bark of the tree, killing it over time. On this day, our group used the EZ Ject only on large ligustrum trees that would have been hazardous to cut down. We also saw a dead chinaberry tree (Melia azedarach) still standing, with an EZ Ject pellet in the trunk, proof that this method works. Seedlings that were too big to pull out by hand were yanked up with a weed wrench or clipped and treated with liquid herbicide.
In a draw by the creek, we found ourselves in a thicket of head-high beauty berry (Callicarpa americana) with hundreds of Japanese ligustrum seedlings growing in the midst. Wondering if there was a mother tree nearby, generating seeds and creating this dense population of seedlings, we looked up, and higher in the draw, 20 feet in the air, almost hidden between tall junipers, we saw the tell-tale shiny green leaves. We located the mother tree, and Julie used a hand saw to cut it down and then treated the stump with herbicide.
At the end of the morning, walking back through the thickets of juniper, yaupon, and beauty berry, it was delightful to see seedlings of escarpment black cherry, wafer ash, oak, and many other natives, knowing that we were giving them a better chance of survival with every ligustrum and nandina we had eliminated.