Billings County Weed Control Board

"You Say it We Spray it"

North Dakota State Noxious Weed List


Absinth Wormwood

Absinth wormwood is a perennial, it is a member of the sagebrush family, and has a large taproot causing it to regrow every year from the base. A key identifier of this weed is its strong sage odor and its light to olive green color. Wormwood thrives in dry soil, making it most often found along road ways and overgrazed areas. The best method of control for Absinth wormwood is with a broad leaf herbicide. 


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Canada Thistle

Canada thistle is a long-lived perennial that can spread by both its roots and seed. Canada thistle has a rhizomatous root system that causes it to spread rapidly, especially in areas that are mowed or disturbed. It can grow anywhere from two to three feet tall and has alternating spiny leaves with toothed edges. Canada thistle is best controlled using a broad leaf herbicide. Please check your 2020 North Dakota Weed Control Guide for specific herbicide recommendations for the area you wish to treat.

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Dalmatian Toadflax

Dalmatian toadflax is a perennial that has a rhizomatous root system. It spreads by both seed and by its roots, the leaves are heart shaped and clasp to the stem. Dalmatian toadflax flowers between June and August. It prefers dry land, disturbed areas, and is often found along road sides. Please check your 2020 North Dakota Weed Control Guide for specific herbicide recommendations for the area you wish to treat. 

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Gibson, D.(2009). Dalmatian Toadflax [digital image].https://www.flickr.com/photos/[email protected]/3916729521/in/photolist-6Y7gek-difqha-Crzjyr-H3P95b-9PtaSG-bCciyN-cmTRV3-cAajnd-cyWcWS-bQRBun-bBWVYd-bBWVNf-2h4QWgn-f6Veaa-bLfWeB-eNy82V-orbHQa-bQRBFK-vUozR8-cmcpns-oFSUE6-nGVe6U-9X1sSf-a8pgJr-2heexvR-a8phs4-2bftwq-21ssGYX-8uxWi9-oYkcWC-cqTyHE-cqSc13-a8pgYR-nDeV1D-irESC-rZJnwv-sn5NuU-nENWWJ-7eo9UK-2i8BBsQ-rweaPM-cp3MAY-V3j8Fb-fw7Da7-bEQfan-V3j94L-kxZfJ-VhMxCe-sFe8ro-ahfiFq

Diffuse Knapweed

Diffuse Knapweed is a short-lived perennial, that reproduces only by seed. It is very invasive and will easily overtake pasture, range, and cropland areas. It flowers between July and August. A key characteristic of Diffuse knapweed is its terminal spiny bracts that are located just below the flower, the flower can be pink, purple, and on occasion white. Please check your 2020 North Dakota Weed Control Guide for specific herbicide recommendations for the area you wish to treat.

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Lavin, M.(2015).Centaurea diffusa [digital image].https://www.flickr.com/photos/plant_diversity/19907425006/in/photolist-2cSZyUJ-ao1RHu-9hno8Z-w7oTF4-21R8TMB-ao1Qey-xSRoNe-25ne2Hp-27kd635-frWi1q-LnPXuj-cDRqU7-2habrzT-xyeZBB-oxw1PW-xJnWkh-oPG7kU-fv6FPi-ehQE6n-2habren-2habrbX-MamNzb-eYZ191-f6ykHF-wMpbgZ-vqs3hS-wk9KsY-w5Rqku-2a1CJtJ-xHgomw-fGKJLJ-roBmAn-wJdQ7P-ogDxSp-4QMCLv-vqAwBk-ogD4dw-4QMCxT-wk9KTC-fMex2p-4QRPRL-sp1DyK-r7354Q-83t34d-xtCnzJ-ehD4ue-4QMCAp-4QMCzc-rowg8q-wzxhCf


Houndstongue

Houndstongue is a biennial weed that germinates in early spring and produces a flower in its second year of life. It commonly creates a flower in late May and early June. It spreads by seeds which are held in a nutlet that are sticky and clings to clothing and fur easily.  Nutlets are often rubbed off by livestock and wildlife causing the seeds to germinate in wooded areas or along fence lines. A major concern with Houndstongue is that it contains alkaloids that are poisonous to horses and cattle. Please check your 2020 North Dakota Weed Control Guide for specific herbicide recommendations for the area you wish to treat.

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Leafy Spurge

Leafy Spurge is a long-lived perennial, that spreads by both seed and roots. A key characteristic in identifying Leafy spurge is the waxy milk like substance that is called latex and is found in all parts of the plant. Leaves and flowers can be broken off and the latex will release immediately. Grazing is not an effective form of controlling Leafy spurge, cattle prefer not to feed on it due to their dislike for its taste and texture from the latex. However, sheep and goats find it palatable. Billings County has very few producers that raise sheep, therefore control through grazing is limited in our County. Plants begin flowering between May and early June. There are several biological control methods that have been proven effective in controlling Leafy spurge. It is often times very difficult to control as it becomes resistant to herbicide treatments if they are not changed regularly.  Please check your 2020 North Dakota Weed Control Guide for specific herbicide recommendations for the area you wish to treat.

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Musk Thistle

Musk thistle is a biennial and reproduces only by seed. It flowers between July and September and can reach heights of up to six feet tall. It tends to grow in areas that are overgrazed, disturbed, and along roadways. A key characteristic of Musk thistle is its large flower which tends to droop and have bracts on the underside that resemble a pine cone. Methods of biological control have not been found to be effective. Please check your 2020 North Dakota Weed Control Guide for specific herbicide recommendations for the area you wish to treat.

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Palmer Amaranth

Palmer Amaranth is a summer annual that spreads only by seed and is a member of the pig weed family. Key characteristics of Palmer amaranth is its petiole length, it has a leaf petiole that is as long or longer than the leaf itself. The leaves are diamond shaped and are wider at the base. It has a very long slender inflorescence which is easily spotted in cropland fields.  Palmer amaranth is highly invasive in croplands and is often hard to control due to its size, herbicide resistance, and seed production. Palmer can be controlled with herbicides in non cropland areas. However, infestations within cropland are best controlled using mechanical methods, such as cutting and burning.  

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Stacey, B.(2014). Palmer's Amaranth[Digital image]. https://www.flickr.com/photos/finaticphotography/15473594916/in/photolist-pzmdFf-onumCY-hX8fuy-fBi8xT-ai2A4B-NHXbpK-dPqv4J-fPr3iW-8jjXow-V1sySa-28MX8mi-d3dCzo-d3dDaQ-hX2Lde-zq7VmU-2ab5d8e-oniJ4s-zq6TJX-A5xpXw-d3dAuS-x7MCz3-x3UNZr-d3dCu3-PeqgtF-2ae1YbU-PeqgoF-d3dzcE-fAjkXA-orvdQZ-o62hGh-o629Cd-EsEtGc-d3fD91-8xkJFu-ygWt1b-8Pwu7e-d3dzpd-BAuNxx-d3fDv5-fAjkGS-onvUGZ-gtUb1E-onvUKp-d3dzwE-r7ox9o-Y51LJD-wnKJ5o-BcKvM7-hX8eRE-d3dzZY


Purple Loosestrife

Purple loosestrife is a perennial forb and has a rhizomatous root system. It is spread primarily by seed but can also spread by its roots. One plant can produce up to two million seeds. Flowering occurs between July and September. It is easily identified by its deep purple flowers and can reach heights anywhere between three to eight feet high.  Purple loosestrife prefers to grow in soils with a high moisture content; therefore, it is most often found in aquatic areas. It is highly invasive and often chokes out native wetland plants and disturbs wildlife habitats. Please check your 2020 North Dakota Weed Control Guide for specific herbicide recommendations for the area you wish to treat.  

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West, L. (2006).looswstrife close [Digital image]. https://commons.wikimedia.org/wiki/File:Lythrum_salicaria,_purple_loosestrife_5.jpg

Russian Knapweed

Russian knapweed is the only perennial in the noxious knapweed family. Unlike the other noxious knapweeds it spreads by its underground root system and not from seed. It flowers between June and September and grows between two to three feet high. Common characteristics that distinguish it from the other knapweeds are its rounded bracts that have transparent tips. Also its roots are a dark brown to black in color, flower colors vary from a light pink, light purple, and can be deep lavender. Infestation can easily choke out native and desirable plants as Russian knapweed is very competitive and easily forms its own monoculture. Please check your 2020 North Dakota Weed Control Guide for specific herbicide recommendations for the area you wish to treat.

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Oldenettel, J. (2007).DSCN3485.JPG[Digital image].https://www.flickr.com/photos/jroldenettel/651253926/in/photolist-ZxR6Y-7bnGJR-2Vz4B7-f3​pzRT-PcSpgF-DDP5k5-PcTL7r-QeEbsA-f3DPd5-2HHMfP-QxoyqD-PSWfXH-eYYbdq-2gCPXHg-2gj7LZm-XhN15y-JhRnCe-Sf6WqQ-6Frpiv-QgjYFW-We3fMs-JhRnAk-L4hKmA-qdpyr8-4UkScy-23ebN1F-L7qEKa-7URRQD-djXMmP-L4hLbm-7URRS4-7UV75w-agEVqV-fLkRzo-YpTqwD-274NYYn-a9DdQH-oq43RD-ZZf8RM-u5xMXH-23A5bqn-5HSp4y-Pa7pUq-6T9yLc-7XAoWy-6T9yLe-ZUwiPL-9LSgUd-dwtUJ7-aPqKLMtal


Saltcedar

Saltcedar is a long-lived perennial and spreads by both seeds and roots if the top growth has been cut or mowed. Saltcedar was introduced as an ornamental and can reach heights up to twenty six feet tall. Its leaves resemble those of evergreens and trees begin to flower in mid to late summer. Flowers vary in color and tend to be shades of either pink or white. Saltcedar can grow just about anywhere but prefers areas within the floodplain along riverbanks and streams. Plants have been known to choke out waterways and can dry up entire lakes if not managed and controlled. Please check your 2020 North Dakota Weed Control Guide for specific herbicide recommendations for the area you wish to treat.

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Spotted Knapweed

Spotted knapweed is a short-lived perennial that is only spread by its seed. Plants range is size from two to four feet tall and flower between July and August. Flowers range in colors from pinks, purples, and on occasion white. The best way to distinguish Spotted knapweed from the other knapweeds is its stiff black tipped bracts that are located just below the flower. Spotted knapweed is very aggressive and spreads rapidly, its seeds can stay viable in the soil for up to five years. Please check your 2020 North Dakota Weed Control Guide for specific herbicide recommendations for the area you wish to treat.


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Yellow Toadflax

Yellow toadflax is a perennial plant that has a rhizomatous root system. It is spread by both its roots and seed. Yellow toadflax was originally planted as a ornamental. The stem and leaves are narrow and though it is shorter it has several similar characteristics of Leafy spurge. The flowers are bright yellow and resemble snapdragons, flowering begins in mid July through September. One plant can produce more than 500,000 seeds per year. Yellow toadflax is very aggressive and can spread in areas up to ten feet each year of growth. It prefers areas with adequate moisture. There are no known herbicides that control Yellow toadflax within North Dakota. 

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Billings County Noxious Weed List


Black Henbane

Black Henbane is a biennial weed that grows primarily in disturbed areas within Billings County. We often find it along road ways and areas where materials have been hauled in or the soil has been disturbed due to construction. Black henbane is poisonous to both humans and animals if ingested. Types of control that have proven to be effective include both chemical and mechanical methods. When the plants are small and have not yet flowered or made seed, chemical methods are most effective. When the plant reaches a couple feet in height and has a true flower, it works best to chop or mow the infestations to prevent seed production. 

Common Burdock

Common Burdock is biennial, meaning it does not make a seed until its second year of life and is spread only by seed. Animals are the primary spreaders of the seed. The burrs are very sticky and easily cling to clothing or fur. Often times burrs become caught on clothing or fur and are transplanted to new areas when the burrs are removed or rubbed off. Common burdock is easily controlled with a variety of broad leaf herbicides and can also be mowed or chopped when it is in its second years of growth and actively producing burrs. 



Hoary Cress

Hoary cress is a perennial weed meaning it comes back every year. Often times it is refereed to as white top. It is spread by both seed and its rhizomatous roots. Seeds can live in the soil and stay viable for up to three years. Hoary Cress is an aggressive plant that thrives in disturbed areas and is commonly found in overgrazed pastures and along road sides. It contains glucosinolates that are toxic to livestock. However, cattle primarily do not graze Hoary cress, but they will eat it in the spring of the year when desirable plants are not actively growing. Hoary cress can be controlled by a select few herbicides. Mechanical control can be done but is often ineffective unless the entire root system is removed.