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Weed of the Week – Sulfur Cinquefoil

Wednesday, October 6th, 2010

Sulfur cinquefoil was introduced into North America in the 1900’s. It began by populating eastern Canada and the Great Lakes region in the U.S. In 1947, sulfur cinquefoil was discovered in Ravalli County, this was the first sighting in Montana. Since the 1980’s, the sulfur cinquefoil population has exploded across the west. This weed has been reported in 33 counties in Montana and occupies approximately 278,000 acres with in the state.

Concerns This weed is adapted to a variety of environmental conditions, it can grow in grasslands, shrubby areas, open forests, roadsides, ditches, and logged areas. It often grows in association with spotted knapweed.

Sulfur cinquefoil is not very palatable to grazing animals. Therefore, in grasslands where this weed occurs grazing will further reduce native grass production. A sulfur cinquefoil plant has the ability to produce up to 1,650 seeds per year. This plant can completely take over a site, creating a monoculture of sulfur cinquefoil.

Identification Sulfur cinquefoil is most recognizable for its yellowish green palamate compound leaves. The 5-7 leaflets are serrated and look similar to marijuana leaves or native strawberries. The plant is 12-28 inches tall and the stem is covered in sparse course, stiff hairs. The flowers of this plant have five, pale yellow petals.

Sulfur cinquefoil is a long-lived perennial that has been documented to live up to 30 years. Sulfur cinquefoil can be confused with the native northwest cinquefoil. They can typically be differentiated among by the backside of their leaves. The native cinquefoil has a silvery-green back side, where the non-native is green. Also, the hair on the stem of the native lays flat against the stem and the non-native has hair that is stiff and perpendicular to the stem.

What can you do? As with any weed management there is no one solution, sulfur cinquefoil is best managed by integrating multiple controls. An effective mechanical method for removing sulfur cinquefoil is hand digging or chopping the root crown out of the ground. Cultivation on crop grounds is also an effective method of removal. There have been a variety of herbicides that have proven to be very effective on controlling sulfur cinquefoil infestations. It is important to revegetate once the sulfur cinquefoil has been removed. There has not been any effective form of bio-control discovered yet because it is closely related to some of our native plants. Getting infestations of sulfur cinquefoil under control takes time and diligence on the part of the landowner. Please call your local weed district, with any questions regarding infestations on your property.

Visit the MWCA Weed ID pages for additional information and pictures of sulfur cinquefoil.

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.

Posts related to: Potentilla recta, Priority 2B Weed, Sulfur Cinquefoil
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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 – Dalmatian Toadflax

Thursday, September 16th, 2010

Dalmatian toadflax was introduced into the west coast of the United States in the late 1800’s. It was brought here from the Mediterranean region as an ornamental plant. It has escaped captivity and now infests much of the northwestern United States. Unfortunately, this weed is still sold in greenhouses as Wild Snapdragon, Butter and Eggs, or Jacob’s Ladder. Dalmatian toadflax was first discovered in south-central Montana in the 1940’s. This weed has been reported in 43 counties throughout the state.

Concerns Dalmatian toadflax is a great concern because it will displace native vegetation and consequently displace animals associated with native vegetation. This weed is extremely successful at displacing native vegetation because it spreads both rhizomatously (roots that run parallel to the ground surface) and by seed. One plant can produce 500,000 seed per year. The loss of native vegetation will also increase soil erosion, sediment yield, and surface runoff due to loss of bunch grasses and sod-forming grasses.

Cattle ranchers are seeing lower carrying capacity on infested sites. Land that has Dalmatian toadflax can have lower appraisal value because of the cost of controlling it and the negative impact the weed has on the land.

Identification Dalmatian toadflax is very similar in appearance to yellow toadflax. The main difference between Dalmatian and yellow toadflax are the leaves. The leaves of Dalmatian toadflax are heart shaped with smooth edges and are arranged alternately on the stem. The leaves and stem are a whitish to bluish in color. The flowers are very similar to yellow toadflax, they are bright yellow with an orange throat and look like a snapdragon flower. Another distinction between yellow toadflax and Dalmatian toadflax is that the Dalmatian can grow up to 3 feet tall.

What can you do? The best strategy for managing toadflax infestations is an integrated approach that focuses on preventing seed formation and vegetative spread. Having multiple approaches to toadflax is crucial because of the wide range of conditions it inhabits and due to its genetic variability. Mechanical methods such as hand pulling and digging are effective in newly established, small patches. Hand pulling toadflax works when the weed is young and the conditions are moist. Mowing will not help reduce toadflax populations because it does not remove the root system. Sheep will graze toadflax when it is in bloom but this is not enough to control an infestation. There are a number of biocontrols being studied; one in particular has shown promising results. This insect is mecinus janthinus and it is a stem boring weevil that causes wilt and suppressed flower production. Herbicides are an effective method for control of toadflax. Revegetation is a very important tool in managing toadflax. Integrating some or all of the above-mentioned tools into a long-term management strategy will help control Dalmatian toadflax infestations. If you have any questions about noxious weeds call the weed district.

Visit the MWCA Weed ID pages for additional information and pictures of dalmatian toadflax.

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 – Cheatgrass

Thursday, September 9th, 2010

Cheatgrass is a regulated plant and not a Montana listed noxious weed.

Introduction Cheatgrass is known by a variety of names including: downy brome, downy cheat, and downy bromegrass. Whatever name you know it by you probably know it is one of the most problematic weeds in Montana. Being a winter annual has given it some advantages over other plants. Winter annuals germinate in the fall and continue to rapidly grow until temperatures are no longer conducive of growth. It is possible under certain conditions that growth will continue throughout the winter, especially in the root system. Germination may occur in the spring as well, depending on conditions. Whether or not it continues to grow throughout the winter, fall germination gives cheatgrass a considerable advantage over most of our natives. In addition to this advantage, cheatgrass has an incredibly rapid growth rate. Five weeks after germination cheatgrass has twice the biomass of desirable grasses that have had the same length of time to grow.

Cheatgrass originated in Asia and was accidentally introduced to North American multiple times in several independent events. Some of the first introductions are thought to be from ship ballast and railroad packing materials. The first report of cheatgrass in North America came from British Columbia in 1890. Cheatgrass was first reported in Montana in 1898 in Missoula County and by 1980 every county in the state had it.

Concerns Depletion of soil water is one of the main processes by which cheatgrass competes with perennial vegetation. It is able to deplete soil water before it is available to other vegetation because of its fall germination and rapid growth. The roots of cheatgrass can be much deeper in the soil tapping into the water table and depleting it before other roots have had the opportunity to reach those depths. It is possible that cheatgrass will diminish the underground water reserves and produce seed for the next generation before the hot, dry part of our summers, leaving no water for other plants that are trying to survive and produce seed.

Cheatgrass has a dramatic effect on the fire regimes on grasslands. Cheatgrass has the tendency to fill in the spaces between bunchgrasses, which increases the fuel for fire and promotes larger and more frequent fires. The shortened interval and increases intensity of fires, due to cheatgrass, makes it difficult for perennial vegetation to recover before the next fire. This leads to an increased population of cheatgrass, which in turn leads to more frequent and intense fires. Eventually the perennial vegetation will be removed from the system and a monoculture of cheatgrass will remain.

Identification Cheatgrass plants can be anywhere from 6-24 inches tall depending on the resources available. At emergence the leaves are browish-green. They turn reddish-purple at maturity. The leaf blades, which are covered in soft hairs, are around 1/32 inch wide and 2-6 inches long. The seed-head droops to one side of the stem and has numerous 3/8-5/8 inch long awns (needle-like extension from the seeds).

What can you do? Prevention is the key! If it is too late to prevent cheatgrass from establishing on your property, which it is for most of us, then there are a few other options. The goal behind controlling and ultimately eradicating cheatgrass is to stop seed production. Cheatgrass is an annual, meaning that every plant dies at the end of the growing season. The only way for cheatgrass to persist in an area is for it to produce seeds every year. These seeds are only viable for up to 3 years. This means that if you can stop your cheatgrass from producing seeds for 3 years, you will have a greatly reduced the population. Some ways to stop seed production are: mechanically (hand-pulling, mowing, weed-whacking), chemically (using herbicides – call the weed district for more information), grazing (it is good forage in the early spring for cattle, sheep, and goats), and revegetation (competition is imperative in reducing cheatgrass populations). The integration of all of these tools is more effective than any of the tools alone. Timing is also very important—mechanical control, chemical control, and grazing all must be done before the plant turns purplish-red (once it is purple seed production is too far along and the seeds will still be viable). If you have any questions about cheatgrass or any other weed please call the weed district.

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

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 – Yellow Toadflax

Thursday, September 2nd, 2010

Introduction

Yellow toadflax also known as butter-and-eggs or common toadflax was introduced into North America as an ornamental in the mid 1800’s. Yellow toadflax has a long history of medicinal uses in Eurasia. The Mennonites cultivated toadflax for dying homespun garments. Yellow toadflax has spread throughout North America and is found mostly in the northeast and Pacific Coast region. In 1973, Alberta, Canada designated yellow toadflax to be “the most troublesome perennial broad-leaved weed in Alberta”.

Concerns

Yellow toadflax is very difficult to remove once the plant has been established because of its ability to adapt to a variety of sites. It also has the ability to reproduce both by seeds and by vegetative roots. This weed will displace desirable grasses and vegetation, which can lead to decreased carrying capacity on rangelands. Yellow toadflax is also said to be mildly poisonous to livestock, though it is generally not palatable to livestock. This tall bunch like weed will shade out vegetation from growing below it and therefore increasing topsoil’s exposure to erosion.

Identification

Yellow toadflax can grow from 8-24 inches tall. The leaves of this weed are gray-green in color and are long and narrow. They are also arranged alternately on the stem. Though the leaves of the toadflax looks like leafy spurge, toadflax does not produce a milky sap. The flowers of a yellow toadflax plant resemble those of a snapdragon with flowers that are 1-1¼ inches long and mostly yellow petals that have an orange throat and a downward pointing spur. They are densely clustered at the top of the stem. Yellow toadflax will bloom between June and July. Each plant can produce up to 8,700 seeds.

What can you do?

The seedlings of Yellow toadflax are poor competitors for soil moisture. It is important to keep a healthy community of grasses and other desirable species to prevent seedlings from establishing. Hand-pulling and digging are useful tools on young plants and small infestation but these methods must be repeated on a long-term scale (10-15 years) to achieve complete control. There are herbicides that have been proven to be useful in combination with mechanical methods and a proper grazing regime. For herbicide recommendations or any other weed questions contact your local county weed district.

Visit the MWCA Weed ID pages for additional information and pictures of yellow toadflax.

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.

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.

Weed of the Week – Common Tansy

Thursday, August 19th, 2010

Common Tansy, photo credit: Jerry R. Oldenettel

Common Tansy is also known as golden buttons and garden tansy. Common tansy was introduced from Europe into colonial North America in the 1600’s as an ornamental plant and for medicinal uses. Ironically, common tansy contains alkaloids that are toxic to humans and livestock if consumed in large quantities. Common Tansy was first discovered in Silver Bow County in 1936. Common tansy is a big problem in most counties on the roadsides, ditches, and waste areas.

Concerns Common tansy is unpalatable to livestock and mildly poisonous. The presence of this weed reduces species diversity, wildlife habitat, and livestock forage. It has a tendency to grow near water, which allows the plant to spread easily and makes control difficult. The root system on common tansy allows the plant to spread laterally and by broken pieces of roots.

Identification Common tansy is a perennial forb that can reproduce by rootstalk or seed. One of the most notable features of tansy is the potent smell cause by crushing the leaves. The flowers on common tansy are yellow-orange button-like flower heads. Flowers of the common tansy are numerous; there can be 20-100 flowers in flat-topped, dense clusters. The leaves on the common tansy are deeply divided into leaflets with toothed margins, almost fern-like. The leaves are alternately arranged and are uniform in size. This plant will grow between 1-6 feet tall and the stem is often a purplish-red color.

What can you do? Due to the extensive root system of common tansy an integrated management approach is necessary. Preventing the spread of this weed into new areas is one of the easiest management techniques. Mowing and hand-pulling has marginal results due to the root system of tansy and they are best used in combination with other controls. Mowing and pulling will help prevent seed production. Maintaining healthy desirable vegetation will aid in controlling common tansy. Grazing in infested areas should be monitored closely to maintain desired species. There are a couple of effective chemicals for common tansy. For recommendations on those, call the weed district,

Visit the MWCA Weed ID pages for additional information and pictures of common tansy.

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 – Blueweed

Thursday, August 12th, 2010

Blueweed - photo by Kellieanne Morris, Ravalli County MT Weed District

Introduction

Blueweed or viper’s bugloss is native to Europe and has invaded much of the eastern U.S. and parts of the western U.S. The first record of this plant in Montana was in 1916. It was listed as a category 2 noxious weed on our state list in March of 2008. Blueweed thrives in gravel bars along rivers and also does well in irrigated pastures.

Concerns
Blueweed can be toxic to horses, sheep, and cattle. The hairs that cover the plant may also act as a skin irritant for humans. This plant can become quite large greatly reducing the productivity of grazable lands due to it being unpalatable. It has the potential to ruin hay due to its high moisture content. It also has the ability to destroy wildlife habitat and native plant biodiversity. It reproduces by seeds that stick to clothing, animal fur, and feathers and may also be disperse by flowing water. Each plant produces between 500 and 2000 seeds.

Identification
Blueweed is most easily identified by its bell shaped flowers that come in shades of blue, pink, and purple. The flowers bloom a few at a time in a scorpoid raceme (resembles a scorpion’s tail). Four or five, usually pink stamen stick out from the center of the bell shaped flowers. Blueweed is a biennial, meaning that it lives for two years. The first year that this plant emerges it is in the form of a rosette. Second year plants typically bolt and produce flowers. The stems are a grayish-green color and are covered with hairs and black dots. The leaves are lance shaped and are also covered with hairs. The plant can be anywhere from 5 inches to 3 feet in height. From a distance it may resemble lupine.

What can you do?

This tap rooted plant can be hand pulled (with gloves and long sleeved shirts) or dug up with good results in small infestations. Mowing can help to reduce the seed production if repeated throughout the growing season but is not a long term solution. Herbicide is an effective control method when applied correctly. Call your local weed district for recommendations on herbicides. As always an integrated weed management plan utilizing all effective means of control and revegetation is the best option for reducing and eradicating blueweed. If you have any questions about blueweed or any other noxious weeds call your local weed district.

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

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.

Posts related to: Blueweed, Echium vulgare, noxious weeds, Priority 2A Weed, Viper's Bugloss
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Weed of the Week – Yellowflag Iris

Thursday, August 5th, 2010

Yellowflag Iris Flower

Introduction

Yellowflag iris, native to Europe, Great Britain, North Africa, and the Mediterranean region can be found almost everywhere in the United States. It is found in wetlands, along the edge of ponds, lakes, or slow moving streams or rivers and is fast becoming one of our most aggressive wetland bullies. This plant can grow in full sun or part shade. When it blooms in late spring to early summer it is unmistakable with its large pale to bright yellow iris flowers. The flowers look very similar to a garden iris but they are often streaked with brown to purple lines. Yellowflag is often mistaken for cattails when the blooms are not present. The best way to distinguish this plant when flowers are not out is to look for the large fruit pod in the summer or the fan-shaped plant-base other times of the year.

Concerns

Yellowflag is a popular wetland ornamental that is still sold on-line. It is very easily spread downstream of its original location both by broken off pieces of rhizome (roots) and by floating seeds. This plant forms incredibly dense stands connected by rhizomes. Several hundred flowering plants can be connected in one rhizome mass. These stands become so dense that they choke out all other native and beneficial wetland vegetation. The dense rhizome masses trap sediment, which reduces water flow affecting fish, plants, and animals. Yellowflag iris is toxic to livestock and other herbivores and the resins that it contains will cause skin irritation in humans.

Identification

This perennial has showy yellow flowers that resemble a typical garden iris. Each stem may have several flowers that each have 3 large downward facing yellow sepals that are streaked with brown or purple lines and 3 upward facing yellow petals. The plant including the flower stalk is 3-4 feet tall. The leaves are mostly basal and are folded around the stem in a fan-like fashion. The leaves will stay green until harsh winter weather begins.

What can you do?

Yellowflag iris is difficult to control both by mechanical means and with herbicide. When hand pulling or digging make sure to wear gloves because of the irritating resins and also make sure to get all pieces of the rhizome mass. One small fragment can start a new mass of plants. To use herbicides on yellowflag an aquatic license is required because of its proximity to water. If you have yellowflag iris on your property or you know where this plant can be found please contact your local county weed district.

Visit the MWCA Weed ID pages for additional information and pictures of yellowflag iris.

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.

Posts related to: Iris pseudacorus, noxious weeds, Priority 2A Weed, Yellowflag Iris
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Montana Weed Control Association

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Weed Articles

Weed of the Week – Sulfur Cinquefoil

Weed of the Week – Field Bindweed

Weed of the Week – Dalmatian Toadflax

Weed of the Week – Cheatgrass

Weed of the Week – Yellow Toadflax

Weed of the Week – Spotted Knapweed

Hoary alyssum–A weed to watch for on your property

Weed of the Week – Common Tansy

Weed of the Week – Blueweed

Weed of the Week – Yellowflag Iris

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