Gaining Control of Woody Encroachment on Pasturelands

Ranchers have observed an increase in woody species, such as western snowberry (or buckbrush) and wolf willow in their pasturelands. With the increase of woody species or brush density; comes reduced acres for livestock grazing.  With the loss of grazing acres, comes a large economic cost. With the increased density of woody species, the grassland is also negatively impacted through a shift in the desired plant community. Major barriers to addressing woody encroachment are, that it is time consuming and costly. When determining the best method to reduce brush, consider the cost of management versus the economic improvements that may occur from elimination of woody species. Some approaches that are being used today to control woody species on pasturelands include cultural, chemical, and mechanical methods.  

Cultural Methods: 

Grazing is a well-known effective way of helping to control brush growth while promoting the development of desired plants. Consider matching the herd size with the area being managed. If the area is too large for the herd, it will result in ineffective control.  

Some livestock species prefer to graze bushes and shrubs. The introduction of small ruminant species that favor eating woody species may help control the spread.  

Prescribed burning is a planned, ignited, and controlled fire that is set to burn unwanted growth and restore desired vegetation. Proper planning, permissions, consultations and safety measure should be adhered to.  Prior to using prescribed burning as a technique, speak with local officials to ensure compliance of regulations, permissions, and procedures are met. 

Chemical Methods: 

The use of herbicides may be beneficial for eliminating woody species; however, this should be carefully thought out. Many herbicides can be harmful to vegetation, people, animals, and the environment. For instance, non-selective herbicides will kill all vegetation, where selective herbicides will potentially eliminate only certain species. Herbicides work best, when they are applied at specific times. Before using herbicides, best practice measures are to read the herbicide labels, directions, recommendations, and consult an agronomist.  

 Mechanical Methods:  

Mechanical methods for weed control involve the use of equipment to manage the brush. It can include using mowers, bulldozers, rollers, choppers, or drags. The type of mechanical treatments used will depend on the time of year, weather, terrain, area, and species. Using mechanical methods to control woody species generally involves repeated, long-term efforts. 

In summary, woody encroachment on pastureland has negative economic and environmental impacts. Early identification and implementation of multiple control methods, appears to be most effective in addressing encroachment on pasturelands. Regularly monitor the control methods, to determine the most cost-effective method.