Bancroft Pond in 2006
We tend to be a little unique here in Western Montana. Many of you know that here in Missoula we walk to the beat of a different drum, just stand on Higgins Ave. any day of the week and you will see people walking, literally to the beat of different drums! All joking aside, we have made great progress over here in terms of raising public awareness of noxious weeds and the importance of using an integrated approach to manage them. This is evident on City Open Space, County Parks and within our VMA’s. The Missoula Valley Yellowflag Iris Eradication Project is one project in particular that deserves attention and has been very successful at raising public awareness about controlling noxious weeds and has generated  overwhelming public support for stopping new invaders.
Until 2001 the bulk of the distribution of yellowflag iris (YFI) in the Missoula Valley was confined to a 1.5 mile section of lower Pattee Creek. In 2001 redevelopment of southwest Higgins Avenue involved updating drainage culverts and resulted in connecting lower Pattee Creek to the Bitterroot River through a series of drainage ditches and ponds. One consequence of altering the path of Pattee Creek was an explosion of YFI in these waterways. After reconstruction the YFI populations expanded to approximately 3.5 miles of drainage ditch between lower Pattee Creek and the Bitterroot River, and completely lined the Bancroft Ponds, a popular urban park. When the Missoula County Weed District mapped the extent of the YFI in order to get baseline data on the infestation, the discovery of several immature YFI where the ditch now drained into the Bitterroot River and this increased the severity of the problem. Land managers in this area recognized the need for immediate response to this problem; if the infestation remained unmanaged it would easily spread throughout the lower Bitterroot and Clark Fork rivers.
In 2004 a collaborative effort was undertaken by multiple partners in the Missoula Valley to begin to address these YFI infestations. The Missoula County Weed District, Missoula City Parks and Recreation, and the University of Montana launched an awareness campaign, targeting residents in the Pattee Creek area as well as the greater Missoula area. This campaign included newspaper articles, direct mailings, door-to-door visits and homeowner group meetings. The partners were pleasantly surprised, as once most residents where informed about the negative impacts YFI has on riparian habitats, they became very supportive of managing this invasive weed.
In 2005 the City of Missoula Parks and Recreation Department began chemical and mechanical control of YFI in Bancroft Ponds Park, home to the largest infestation of this plant in the valley. A commercial applicator sprayed the infestation with an 8% solution of aquatically labeled glyphosate and a team of interns mowed mature flowers for a ¼ mile upstream of this infestation to reduce seed input into the pond. The city continued these same controls on these infestations in 2006.
In the spring of 2006 Missoula County Weed District staff and a team of University of Montana interns went door to door in neighborhoods at the upstream end of the infestation handing out educational materials about YFI and the eradication campaign. In the spring of 2006 landowners in the Pattee Ck. Vegetation Management Area became involved with the project and a commercial applicator was hired to treat the upper ½ mile of the infestation; all of which was on private lands. Along this stretch of creek concentrated aquatic glyphosate was injected into flower stalks. This helped to eliminate the possibility of non-target damage to the many ornamental plantings landowners have established along the creek. In the fall of 2006 the University of Montana treated several infestations at a flood control pond within the project area.
In 2007, the project received a grant from Noxious Weed Trust Fund to treat the entire project area. This increase in funding for the project coupled with promising   results from 2005-06 controls for the first time partners felt confident that eradication of YFI in the Missoula Valley was actually achievable. The treatments have moved away from stem injection, to precision spot spraying with a backpack. Stem injection proved to be too labor intensive and not as effective as foliar application. The entire project area was treated again in 2008, with huge reductions in infestation size and frequency. In 2009 we again received a grant from the Noxious Weed Trust Fund. In the 2009 field season some sites no longer need to be treated but where still monitored for seedling germination. In the past five years, we have observed as much as a 90% reduction in YFI across the project area, with complete eradication at many sites. Yearly monitoring of all areas will continued to assure no seedlings emerge as the seed viability of YFI isn’t well documented.
Bancroft Pond in 2009
Each field season we maintain contact with our landowners and each year we are encouraged by the positive response from the landowners. Â From the beginning of the project educating the public on the negative environmental impacts of noxious weeds and instilling a vision of attractive replacements for YFI was critical for getting support from a largely skeptical public. Partners (public and private) are now working on restoring the ponds and urban wetlands present in Bancroft Ponds Park, with the hopes that this site will serve as a restoration demonstration area. On Halloween of this year volunteers from across the project area held a planting day, where we planted Rocky Mountain Iris, Blue Camas, Yellow Monkey Flower and spread a native riparian seed mixture.
Call us what you want… Granola, Hippies, Freaks. But remember we are all in this battle together, working towards a common goal of protecting Montana from the invasion of noxious weeds. And bite your tongue because your kids may someday be going to school here and if they do, they may like it so much they never leave!
