Working together to strengthen and support noxious weed management efforts in Montana.

invasive plants

Montana Action Plan for the Biological Control of Invasive Plants

Wednesday, January 28th, 2015


The Montana Biological Control Working Group has produced the Montana Action Plan for Biological Control of Invasive Plants.   Download your copy of the document: Montana Action Plan for Biological Control of Invasive Plants

This was produced by: The Montana Biological Control Working Group (MBCWG) was convened in 2008 as a functional unit under the Montana Weed Control Association’s Integrated Weed Management Chair. The MBCWG is an open membership group comprised of interested stakeholders including private individuals and participants from state, federal, county, and other organizations. The MBCWG is charged with developing a structure to assist in and improve the current methods for the redistribution and monitoring of biological control agents in the state of Montana. Our plans are to identify any deficiencies in the current implementation of weed biological control in Montana and suggest measures to improve biological control as a weed management tool.
The mission of the group: To advance the use of biological control as an integrated management tool to reduce invasive weeds and their impacts in Montana

Invasive plants in wildland ecosystems: merging the study of invasion processes, with management needs

Wednesday, July 17th, 2013


Introduction: Increasing numbers of non-native species threaten  the values of wildland ecosystems. As a result, interest in and  research on invasive plant species in wildland  settings has accelerated. Nonetheless, the ecological and economic impacts of non-native species continue to grow, raising the question of how to best apply science to the regulation and  management of invasive plants. A major constraint  to controlling the flow of poten­tially undesirable  plant  species is the lack of a strong  regulatory framework  concurrent  with increases in trade volume. To address this, ecologists have been developing models to predict which species will be harm­ful to wildland  values and are working with the horticultural industry  to apply this information to the sale of species. The management of established invasive plants is hampered  by conflicting goals, a lack of information on management outcomes, and a lack of funding. Ecologists and weed scientists can provide a scien­tific basis for prioritizing species for control and for managing species composition  through  the application of  control  technology,  which  can  take  place  simultaneously with  the  manipulation of  the  ecological processes that influence community susceptibility  to invasion. A stronger scientific basis for land management decisions is needed and  can be met through  nationally  funded  partnerships  between university and agency scientists and land managers.

Authors: Carla MD’Antonio, Nelroy  E Jackson, Carol  C Horvitz ,and Rob Hedberg

Download and read the complete Research Report on Invasive Plaints in Wildland Ecosystems..

MSU May Weed Post – New Invaders

Friday, May 17th, 2013


The May Weed Post  features three “new” invasive plants—white bryony, big-headed knapweed, and medusahead.  These exotic species aren’t “new” to North America and are even on the noxious weed list in some western states.  But they might be “new” to you, so here is an opportunity to learn more about them so if you ever come across them in the field you’ll be more likely to know what they are.

Download and read all about the new invaders in the May MSU Weed Post

If you have suggestions for any other “new” weeds you’d like to know more about in future Weed Posts, please let Jane Mangold at MSU know.

2012 North American Invasive Plant Ecology and Management Short Course

Friday, May 18th, 2012


In just over a month the 2012 NAIPSC will take place in North Platte, NE. Organizers have extended the registration deadline for the 3-day course to June 18, 2012. If you are thinking about attending the NAIPSC and have not been able to decide, here are some things to consider:

The 14 instructors teaching at the NAIPSC represent 8 states, including North Carolina, Kansas, Wyoming, Montana, Oregon, Idaho, South Carolina, Nebraska, and Oklahoma.

  • There will be 3 separate workshops on topics related to plant identification, invasive plant physiology, and technology for locating and mapping plants.
  • The materials provided to participants include 3 books, a CD for identifying plants in North America, and the 2012 NAIPSC binder.
  • All participants will enjoy catered lunches and breaks each day, and a BBQ dinner/tour of the historic Buffalo Bill Ranch house and barn.

This is just a sampling of the offerings at the 2012 NAIPSC. Each day will be filled with activities and information that will help participants answer questions, address challenges, or gain new understanding related to invasive plants.

Check the website ( Plan to attend today! You’ll be glad you did!

Contact:  Steve Young []

Weed of the Week – Orange Hawkweed

Thursday, October 28th, 2010


Orange hawkweed is native to Europe and likely came to the U.S. as an ornamental.  It has since escaped cultivation and was first found to be a problem in Spokane, WA in 1945.  There are serious infestations in northwestern Montana, northern Idaho, and northwestern Washington.

Orange hawkweed’s clusters of bright orange to orange-red dandelion-like flowers make it unmistakable.  The orange flowers follow the path of the sun throughout the day and if the plant is broken off it exudes a milky latex substance.  There are several native species of hawkweeds in Montana but orange hawkweed can be distinguished by its orange flowers (it is the only species with orange flowers), bristly hairy leaves (most other species have smooth leaves), and stiff black hairs up the stem.

Concerns Orange hawkweed is a great concern because of it ability to reproduce several ways.  The clusters of 5-30 flowers produce between 12 and 50 seeds per flower and these seeds remain viable in the soil for up to 7 years.  This plant can also spread or reproduce from stolons (above ground runners), of which it produces an average of 6 per year, rhizomes (underground horizontal roots), or adventitious root buds (buds on the roots that can develop into a new plant at any point).  Not only does it have the ability to spread in a variety of ways but it is also believed to be allelopathic (exudes toxic chemicals into the soil that suppress surrounding vegetation).  The combination of these abilities makes it a very aggressive species that can rapidly create large, dense monocultures pushing out not only native, beneficial vegetation but also established lawns.

Identification This perennial has a basal rosette with many hairy leaves and a leafless, hairy stem that can be up to 30 inches tall.  Each rosette is capable of producing 10-30 flower stems, each of which have 5-30 orange flowers that are arranged in a flat-topped cluster.  The flowers are bright orange to orange-red and dandelion-like in appearance, with square ended petals.

What can you do? Due to the extensive root system of orange hawkweed hand-pulling and digging-up large infestations is not an effective means of control.  Very small infestations may be controlled by these methods but care must be taken to remove all of the root system because even the smallest fragment can produce a new plant.  Mowing is not recommended because it actually encourages the growth of this plant.  There are several herbicides that are effective in controlling orange hawkweed and re-seeding is always recommended to fill in the areas where this plant was removed.  If you have any questions regarding orange hawkweed or any other weed call your local weed district.

Visit the MWCA Weed ID pages for additional information and pictures of orange hawkweed.

This series of articles was developed by Ravalli County.  If you would like to use these articles please contact Ravalli County Weed District Weed Coordinator at (406) 777-5842.

Weed of the Week – Field Bindweed

Thursday, September 23rd, 2010


Field bindweed was introduced from Eurasia in the 1800’s.  It is unclear whether this weed was brought here as an ornamental or by accident.  Other common names that field bindweed is known as are: perennial morning glory, creeping jenny, bellbine, sheepbine, and corn-bind.

Concerns This perennial weed will grow into a dense tangled infestation.  Field bindweed will inhabit pastures and cultivated fields as well as other disturbed areas.  The creeping nature of bindweed forces out native grasses and forbs creating pure fields of field bindweed.  Field bindweed is very difficult to control due to its vigorous root system and its ability to lay dormant for up to 60 years.  The roots of the field bindweed can extend up to 15 feet deep.

Identification Field bindweed is part of the morning glory family and shares the family’s vine characteristic.  The stems of this weed will grow between 1-4 feet long, creeping horizontally along the ground or climbing fences and other structures.  The leaves are shaped like arrowheads, are dark green, and grow alternately along the stem.  The most notable feature of this weed are the flowers.  They are 1 inch in diameter and are bell-shaped. There are two bracts located on the stem below each white to pinkish flower.  Four small seeds are produced by each flower and are located in the round fruit.

What can you do? The control of field bindweed requires a persistent effort.  The prevention of new infestations is the cheapest and easiest method for control.  Cultivation can be effective if repeated throughout the growing season especially on new infestations.  Competitive planting with crops such as alfalfa, cereal grains, and corn have been shown to reduce bindweed growth.  Shrubs and trees with vegetation planted below them have also shown to reduce bindweed growth.  Landscaping with plastics and fabric can be used in areas where it is conducive.  This method excludes light to the plant and may take three years to kill the bindweed plant.  There are herbicides that are effective on bindweed.  For herbicide recommendations or any weed oriented questions call your local weed district.

Visit the MWCA Weed ID pages for additional information and pictures of field bindweed.

This series of articles was developed by Ravalli County.  If you would like to use these articles please contact Ravalli County Weed District Weed Coordinator at (406) 777-5842.

Weed of the Week – Spotted Knapweed

Thursday, August 26th, 2010


Notice the dark spots on the bracts under the blossom, this is where the weed gets its name Spotted Knapweed.

Notice the dark spots on the bracts under the blossom, this is where the weed gets its name Spotted Knapweed.

Introduction Spotted knapweed is the number one problem on rangelands in western Montana.  Spotted knapweed is dramatically interfering with the Montana’s unique ecosystems.  It was accidentally introduced to the United States through contaminated alfalfa and contaminated soil used as ship ballast.

The first report of this weed in Ravalli County was 1921.  Knapweed has infested 2-5 million acres in Montana, with potential to spread to the 34 million susceptible acres in the state.  Spotted knapweed has been recorded in every county in Montana.

Concerns Knapweed has changed the face of our lands in western Montana.  Ranchers, wildlife enthusiast, hunters, foresters, hikers, and fisherman are impacted by the dramatic affect that knapweed is having on our ecosystem.  Spotted knapweed is particularly hard to manage due to its ability to occupy a variety of sites and habitats.  This weed will aggressively out-compete native vegetation.

Watersheds throughout the state are reaping the negative effects of the soil erosion that knapweed causes.  The soil erosion caused by spotted knapweed is degrading fisheries and water quality.  Spotted knapweed is impacting Montana’s economy in a serious way. The negative effect knapweed has on Montana’s economy is an estimated $42 million annually.

Identification Spotted knapweed is a pinkish-purple flower and the plant grows 1-3 feet tall.  The bracts underneath the flowers have dark spotted tips that are also fringed.  Spotted knapweed blooms from mid to late July and through September.  Each individual flower will bloom for 2-6 days.  The flowers will reopen after 20 days to disperse seeds.  One knapweed plant can produce up to 1000 seeds and remain viable in the soil for 8 years. You will begin to see spotted knapweed rosettes in early April.  Knapweed can grow to nearly 4 feet tall on moist sites.

What can you do? For pastures and rangelands that have not been infested, prevention is key.  Avoid transporting seeds from infested sites.  Seeds can attach themselves to vehicles, clothes, and animals.  Use only certified weed-seed free seed and hay in non-infested areas.  For infested areas integrated weed management methods need to be employed.  Small infestations can be controlled through timed hand pulling, which should take place when the soil is moist and prior to the plant going to seed.  Pulled plants should be bagged and disposed of or burned.

Plowing an infested area is feasible, if plowed down to 7 inches below soil surface and if the area is reseeded with desirable vegetation.  Plowing may cause dormant knapweed seeds in the soil to germinate.  This method is best if used with herbicide treatment or grazing.  Sheep, goats, and cattle will graze spotted knapweed at certain times.  Grazing on knapweed should be timed for when the grasses have gone dormant.  Sheep grazing in combination with herbicide use can be fairly effective.  There are multiple insects that exist in Montana as a mean of controlling knapweed.  The success of knapweed eradication requires a long-term commitment.

Visit the MWCA Weed ID pages for additional information and pictures of spotted knapweed.

This series of articles was developed by Ravalli County.  If you would like to use these articles please contact Ravalli County Weed District Weed Coordinator at (406) 777-5842.

Hoary alyssum–A weed to watch for on your property

Friday, August 20th, 2010


Dr. Jane Mangold, MSU Assistant Professor and Extension Invasive Plant Specialist, just published an article about a weed to keep an eye out for during the late summer.    The following is an excerpt from her article:

Have you noticed a small, white-flowered mustard growing prolifically in your neighborhood? It could be the noxious weed hoary alyssum (Berteroa incana). Hoary alyssum was added to the state noxious weed list in 2008, and may not be as familiar as other notables like spotted knapweed, Canada thistle or leafy spurge.

However, if you live in southwestern Montana, where this weed is most prevalent, you’ve probably seen it along a bike trail or road, in a waste area or pasture, or even in your yard. It flowers from spring through late fall, and is currently very noticeable as other vegetation begins to die back for the season.

Read the complete MSU news article here.

Visit the MWCA Weed ID pages for additional information and pictures of Hoary alyssum.

New Alien Invasive Species Awareness Campaign

Sunday, June 6th, 2010


Montana Fish, Wildlife & Parks has started a new awareness campaign aimed at aquatic invasive species.

They have new television spots and materials available.  Some of the new materials include:

  • Postcards
  • Posters
  • Fliers
  • Bumper Stickers
  • Media Kits

Contact Eileen Ryce, ANS Coordintor, at Montana FWP for more information on how to obtain these materials (406) 444-2448.