Note: Although this article focuses on the Lewistown Field Office, similar weed control techniques are used in Bureau of Land Management offices across Montana/Dakotas.

Noxious weeds present a continuously robust problem for public land managers. Every year established weed patches try to expand, and new patches seem to appear as quickly as bills in the mail.   

The seeds from noxious weeds spread easily — some through natural patterns, such as wind or flowing water; others through the movements of humans, livestock or wildlife. Weed seeds can also hitch a ride on the wheels or undercarriage of vehicles before falling off to start another infestation.

Controlling or eliminating noxious weeds is not easy.

For those BLMers involved with noxious-weed management, the importance of being creative and making a dollar go as far as possible has never been greater.  Noxious weeds are a national concern on public lands; and over the years, the weed infestations have grown. On average, the BLM’s budget to address noxious weeds has not grown as fast as the collective weed patch.

To respond to this continuous tug-of-war, the Lewistown Field Office has developed an innovative, efficient, and cost-effective weed-control program that relies heavily on the assistance of livestock grazing permittees.

Through cooperative agreements, livestock grazing permittees agree to complete the labor portion of weed control on the BLM land they graze. BLM agrees to provide herbicide or biological-control agents; recommend rates of application; conduct inventories, monitor infested sites; and, in some cases, provide equipment assistance.          

This cooperative effort has evolved into an extremely cost-effective program in the endless war on noxious weeds. The Lewistown Field Office is extremely fortunate to work with a group of grazing permittees who have demonstrated an exemplary level of awareness and dedication to noxious-weed control.             
“The effectiveness of our weed-control program depends on this cooperation and we applaud our permittees for their efforts,” said Lowell Hassler. Hassler is a natural-resource specialist in the Lewistown Field Office who manages the cooperative agreement program.

Other Weapons in the War on Weeds

The Lewistown Field Office also uses a variety of other methods in the effort to keep noxious weeds at bay.

“Our noxious weed-management program has grown to include several biological-control insectaries, which serve as distribution centers for private and public land throughout the western United States,” Hassler said. “These insectaries include various species of agents (bugs) in a wide range of stages, varying from experimental to distribution.  The weed species targeted by our biological control efforts include leafy spurge, spotted knapweed, Russian knapweed, Canada thistle, Dalmation toadflax, poison hemlock, salt cedar, hound’s-tongue and hoary cress (whitetop).”

Each year BLM hosts a bug-gathering day at one or several of these insectaries. BLM staffers and landowners venture into the insectary, armed with fine mesh nets and cups to hold their catch. On a calm day, participants may net multiple thousands of bugs, which they transport via Styrofoam cups (with lids) and release onto new sites.  These gathers are popular events among landowners interested in using biological control on their properties.    

The Lewistown Field Office has also entered into cooperative agreements for weed control using domestic sheep grazing. This program is very effective, but it is limited to geographical areas with concentrated weed infestations and adequate water supply for large bands of sheep.           

In addition, the Lewistown Field Office targets specific weed infestations at specific locations around the state for chemical applications by sponsoring cooperative weed-control days with other agencies and public entities. These efforts are generally geared toward a fun, educational, and productive days in the battle against noxious weeds.

BLM also works cooperatively with the county weed departments in the nine counties that make up the central Montana zone.

“We’ve found that it takes a full tool box to make progress or just stay even with the rate of spread we’ve seen with noxious weeds,” Hassler said. “Each of these methods has its place on the landscape, but our cooperative agreements with grazing permittees are certainly the most effective means we’ve found for keeping noxious weeds at a manageable level.”