Texas: 2 Invasive Mexican Grasses Turning Up In State – Info You’ll Need

Mexican needlegrass. (Texas A&M AgriLife Extension Service photo by Dr. Morgan Russell)

Mexican needlegrass. (Texas A&M AgriLife Extension Service photo by Dr. Morgan Russell)

The Texas A&M AgriLife Extension Service has new publications on two opportunistic and invasive grasses from Mexico now spreading into some Edwards Plateau and Concho Valley pastures, said Dr. Morgan Russell, lead author of both publications.

Russell, AgriLife Extension range specialist at San Angelo, said the culprits are Mexican needlegrass, which is infiltrating mostly from oil and gas operations, and Mexican feathergrass, a popular ornamental, which is escaping landscapes and cropping up on rangeland.

The publications are Mexican Needlegrass by Russell and Dr. Roger Q. “Jake” Landers, AgriLife Extension range specialist emeritus, Menard, and Mexican Feathergrass by Russell and Dr. Barron Rector, AgriLife Extension range specialist, College Station.

“Mexican needlegrass is an introduced species from Mexico, though we don’t know how it first got here,” Russell said. “Range professionals are getting more questions about it as ranchers notice the grass in their pastures, mostly along disturbed sites such as oil and gas locations, pipelines and along caliche roads.”

Russell said identification is straight-forward as the grass is very noticeable when spotted in pastures.

“It can look a lot like Texas wintergrass, which is a very common species to most ranchers here,” she said. “But it is much rougher and coarser with very saw-toothed leaves that scratch when you wrap your hands around it. You can really feel those edges and know what you’re dealing with. That texture is why livestock mostly shun it.”

Mexican feathergrass. (Texas A&M AgriLife Extension Service photo by Dr. Morgan Russell)

Russell said Landers first noticed the grass more than 30 years ago in Menard County and wrote a paper on it in the 1980s.

“But then the flurry of interest waned until today when we are seeing a surge in Mexican needlegrass population and density, so we are focusing more on it now and are using some of that earlier work that Dr. Landers provided Texas A&M AgriLife.”

 The other pest, Mexican feathergrass, is a common plant material in the region’s landscape trade, Russell said.

“It’s kind of ironic that Mexican feathergrass is such a threat to native pastures,” she said. “It’s a great ornamental grass here and you see it all over. It’s very fine textured with a pretty seed head and it doesn’t become overgrown like some other grasses do in the landscape. Aside from its beauty, its popular because it’s so well adapted to dry arid environments and very shallow soil. It can practically be planted in a flower bed and walked away from and it will maintain itself.”

Russell said problems occur when it escapes those flowerbeds into native pastures.

“In some areas where it has escaped, we are noticing prolific seed production and establishment in nearby ornamental landscapes and also in pastures surrounding those ornamental landscapes,” she said. “Consequently, we’re watching rangeland being invaded by this grass in some areas.”

Russell said Mexican feathergrass has been declared a noxious species in California and a couple of other Western states, but not in Texas, though the potential and opportunity exists for it to become a problem.

“The more word we get out to groups and individuals buying this grass for ornamental purposes, the better educated and informed they and the general public will be concerning this grass,” she said.

Mexican feathergrass is palatable, she said, but only during the prime growing season.

“Once it produces its seed head, it rapidly deteriorates in palatability and nutritional value, so most grazing livestock given the choice will venture away from it to graze more desirable forage. Doing so further gives this invader a competitive edge as the better plants are eaten, thus lessening the competition for water and nutrients.

“We’ve had some cold weather and these grasses will be going dormant if they are not already,” she said. “They are perennial though and will green up again next spring, so producers should make a point to keep an eye out for them next year.”

For information on these and other rangeland issues, contact Russell at 325-653-4576 or  morgan.russell@ag.tamu.edu.