Weeds and Pests
Announcements and Upcoming Events
New Population of Palmer Amaranth Detected in Montana: Be on the Lookout for Palmer Amaranth and Waterhemp this Fall. Please contact our office if you suspect you have spotted any Palmer Amaranth.
|MSU Extension Services has a variety of MontGuides and other helpful publications on a broad range of topics from agriculture to raising a family. If you don't see what you are looking for on our website, there's a good chance that you may find it on the MSU Extension website.
Articles and Useful Links
|Data on noxious weeds found in Montana.
|Proper storage and cleaning techniques can add years to the life of spraying equipment. This fact sheet offers tips for preparing pesticide spraying equipment to be stored for the winter, including a list of which cleaning agents are most effective for various pesticides.
|Fire can be a useful tool for producers, and it can improve forage quality for the first growing season following a fire to aid in reducing invasive species and improving range conditions. However, there are rules and regulations that must be followed when conducting a prescribed burn. In all prescribed burns, authorities should be contacted and weather conditions, such as relative humidity and wind speed, should be monitored closely.
|Kochia (Kochia scoparia or also Bassia scoparia) and Russian thistle (Salsola kali) are the most problematic broadleaf weeds in Montana cropping systems. Over the last 70 years, but especially after the transition to no-till, these weeds have been managed using herbicides, however evolved herbicide resistance is making management harder.
|Preventing the spread of waterhemp in Montana is a high priority. This guide provides information on waterhemp identification, why it’s problematic, and what actions to take if you suspect you have found it.
|MSU Pesticide Education Program link.
|Describes the life cycle of the two cutworms, how to identify, monitoring adults and larvae, damage caused by them, and how to decide between control options: chemical, cultural management and biological control.
|Mosquitoes are serious nuisance pests due to their persistent biting behavior and are responsible for affecting the health and well-being of humans, companion animals, livestock and wildlife.
|The purpose of this publication is to instruct pesticide applicators to use proper
PPE, including how to read the product label, understand chemically-resistant materials
and types of PPE, how to clean PPE, and best practices to reduce exposure.
|This MontGuide describes black henbane's biological and ecological characteristics. It also provides mechanical, cultural and chemical management options to control this species.
|Poison hemlock is a toxic weedy plant in the parsley or carrot family that occurs where moisture is adequate and disturbance is frequent. Proper identification and management can help to prevent poisoning of livestock, wildlife, pets, and even humans.
This link provides useful information regarding herbicides including the MSDS.
2024 Monthly Weed Posts
January 2024 (pdf)
|To DIY or Not to DIY: Why Use Registered Herbicide Products?
2023 Monthly Weed Posts
|Revegetation Guidelines: Considering Invasive and Noxious Weeds Revegetation, the intentional planting of desired species, is an important component of integrated weed management. Weed control without revegetation can be short-lived if desired plants are not available to occupy open spaces created after weeds are killed.
|Schutter Diagnostic Lab: 2022 Plant Identification Updates.
|Noxious or Native? Leafy spurge (Euphoriba esula) and Western gromwell (Lithospermum ruderale).
|Common Teasel (Dipsacus fullonum)
|Ventenata dubia (pdf)
|Grass Identification Basics is the June Monthly Weed Post. There are many reasons to learn to identify grasses, but it can be challenging because different species look similar to one another at first glance. Grass identification requires looking at characteristics that are small and typically not as showy as the bright and colorful petals of broad-leaved wildflowers. This video covers basic grass anatomy and helps explain terms commonly used for grass identification.
|Mowing to Manage Invasive and Noxious Weeds
|Canada thistle (Cirsium arvense) is a perennial weed that causes significant economic losses in agriculture.
|Common tansy is an exotic perennial forb in the Asteraceae family that is on Montana’s noxious weed list. It inhabits higher moisture, disturbed soils, and can be found in places like meadows and riparian areas as well as along roadsides, ditches, and railroad tracks.
|Tall tumblemustard is an exotic species in the mustard family. This species grows throughout Montana, inhabiting disturbed soil of grasslands, agricultural fields, streambanks, and roadsides from low to mid elevations.
2022 Monthly Weed Posts
|Common Buckthorn (Rhamnus cathartica) Common Buckthorn is a noxious weed in several other states in the upper Midwest and Northeast and was placed on the Montana noxious weed list in 2017.
|Seed Dispersal by Vehicles and the Value of Washing Vehicles to Prevent Weed Spread is the topic for the November 2022 Weed Post.
|Yellow Mignonette is a troublesome high seed output noxious weed that is the subject of October's Monthly Weed Post.
|No Monthly Weed Post this month.
|August Monthly Weed Post highlights the Western Salsify
|The Fragrant Water Lily, also known as American Water Lily, White Water Lily or simply invasive water lily is the focus of the July Monthly Weed Post.
|This month we are looking at Identifying Invasive Annual Grasses in Montana.
|Creeping Bellflower also known as rover bellflower or rampion bellflower is the May Monthly Weed Post.
|Curious what a particular plant is? Your smart phone may have an app for that!
|This month we are looking at Cinquefoils (Potentilla Species) and the difference between Spotted Knapweed versus Dotted Blazing Star
|Noxious Weed Views and Behaviors After 25 Years of Education and Outreach
Flowering Rush is the subject of our first Monthly Weed Post for 2022.
2021 Monthly Weed Posts
|Noxious Weed or Native Plant? Watch this video on Noxious Weeds and Native Plants to learn more.
|Chicory or more commonly known as Blue Daisy or Corn Flower is in the Monthly Weed Post spotlight this month.
|The Milfoil Weevil is a small aquatic bettle that is native to North America. This month we are looking at the Milfoil Weevil's impact here in Montana.
|Testing Indaziflam for Restoring Cheatgrass (Bromus tectorum) Infested Montana Rangelands
|The August Monthly Weed Post offers some important information for Preventing Weed Invasion from Hay Shipments in the short and long-term.
|Tips for managing noxious weeds during drought including Spraying for Noxious Weeds During Drought can be found in the July Monthly Weed Post.
|Does Vinegar Kill Weeds? Find out in this Monthly Weed Post.
Our May Monthly Weed Post features Baby's Breath (Gypsophila paniculata).
Additional information on Baby's Breath (Gypsophila paniculata)
|Adult weevils begin to emerge from the soil in the spring. This month we are looking at the Houndstongue Root Weevil.
|Effects of Increased Temperature and Carbon Dioxide on Cheatgrass and Ventenata.
|Puncturevine (Tribulus terrestris) or more commonly known as goatheads is now found in all western states of the US. This invasive noxious weed was first recorded in Montana in 1938.
|No Monthly Weed Post this month.
Articles and Useful Links