Field bindweed , a deep-rooted perennial weed that is well adapted to Texas climate and environment, is a native of Europe and western Asia and was introduced to this country during colonial days. The species is found across the United States, except in a few very southwestern states where the climate is not favorable for growth. It is a problem primarily in grasslands and farming areas of the Great Plains and Western states.  

Although native to Texas, this heavily-thorned tree is considered invasive because it can quickly move into grasslands and out-compete native plants grasses for living space, often creating monoculture stand where nothing else is present. Refuge staff use a forestry cutter in thick stands of locust, followed by spraying with an approved pesticide to prevent re-sprouting. 

Several invasive plants are an issue on the refuge. The most common is Johnsongrass - an invasive, perennial grass that invades roadsides and disturbed areas, crowding out native plants. Refuge staff actively spray Johnsongrass with approved pesticides in an effort to control its spread within the upland areas.  

Red cedar, native to this area, provides food and shelter for birds and mammals, but it is also very invasive in grasslands. Within just a few years without fire (which used to occur naturally) or mechanical removal, cedar trees will monopolize an open, grassy field and change the entire ecosystem. They are commonly found along fence rows – deposited there by birds who have eaten then deposited the seeds. Although slow growing, cedars can become very large and live for a 100 or more years. Refuge staff and volunteers are working to remove cedars from prairie restoration sites. 

Introduced from Japan as an ornamental in the late 1800s, shrubby lespedeza is a perennial member of the pea family that is now an extremely aggressive invader of open areas. It often forms dense thickets, which displaces native vegetation. When found on the refuge, this species is sprayed with an approved pesticide.