UM Crew to Spray Noxious Weeds on Mount Sentinel

May 11, 2020


UM News Service

MISSOULA – A crew of workers from the University of Montana will spot spray noxious weeds on Mount Sentinel between May 14 and July 3. The group of four to six people will work from about 7 a.m. to 3 p.m. Monday through Friday, weather permitting.

Noxious weeds are a legal category of non-native, invasive plants that must be controlled by all landowners. UM has worked hard over the past 21 years to control noxious weeds and promote restoration and conservation of native prairies on Mount Sentinel.

 “These are backpack applications on specific plants,” said Marilyn Marler, UM natural areas manager. “We include a bright blue dye in the tank mix so that people can see what areas have been sprayed.” 

The spray mix is Tordon 22k, which controls leafy spurge, Dalmatian toadflax and spotted knapweed, with a small amount of MSM 60 to control invasive tumble mustards that have been a problem in recent years.

The crew will work below the Fire Road for most of the season. UM property on Mount Sentinel includes the area around the M Trail, but also low on the mountain from East Beckwith Avenue south to behind UM Family Housing near the UM Golf Course. Signs with maps will be posted at trailheads. If you have questions, call or text Marler at 406-544-7189 or email

UM has established all of the available biocontrol insects for Mount Sentinel’s noxious weeds, and also relies heavily on community volunteerism for weed pulling. The COVID-19 situation required the cancellation of several volunteer events this spring, but Marler hopes to welcome back UM students and community volunteers next spring.


Contact: Marilyn Marler , UM natural areas manager, 406-544-7189,