More than 30 species of yucca grow in Texas. Yucca infests some 19 million acres of rangeland, mostly in the western two-thirds of the state. Some species are considered desireable. For example, Spanish dagger is an attractive plant and both deer and livestock relish its flowers and fruits. Most species of yucca, however, are considered problem plants because they develop dense stands. Species such as twisted leaf yucca may need to be controlled.
A Yucca plant has one or more whorls of leaves with a common root crown. yucca leaves are long, straight, very sharp-pointed, very fibrous, and covered with a thick layer of wax. There are no broadcast herbicide treatments for yucca, but it can be controlled with individual plant treatments.
Here are two, three-step ways to control yucca. They are easy to use, environmentally responsible and effective. One method uses a low-volume herbicide + oil spray in each whorl, and the other method treats each whorl with undiluted herbicide. Using these Brush Busters methods, you will be able to selectively kill unwanted yucca plants with no damage to desirable vegetation.
Keep in mind that controlling yucca is not a one-time job. Livestock, wildlife, wind and water spread the seeds far and wide, so you will need to search for unwanted seedlings periodically and kill them.
Professionals with Texas AgriLife Research and Extension Service have developed, tested and approved these yucca control methods. Your results may vary, but you should be able to kill about seven of every ten plants treated.