obnoxious weeds - university of minnesota · pdf fileslide 9 tansy (tanacetum vulgare ) steve...

Invasive, Noxious or

Obnoxious WeedsWhat’s the Difference?

Created by: Lynne HagenUniversity of MN Extension

Anoka County Master Gardener

Updated 2011

Introduce yourself

Slide 2

Photo: MN History Center

Minnesota is home to three biomes: prairies to the southwest, deciduous forests in the east-central part of the state and boreal (coniferous) forests to the north bordering along Canada. Virtually untouched by human impact prior to the 19th century, the landscapes were flourishing with native herbaceous plants and trees. Within a few decades the landscape changed dramatically. This was due to the development of farms, towns and cities. The rapid expansion of immigration and settlement resulted in a loss of native habitats and the introduction of thousands of exotic and invasive species of plants and creatures. “Species that have been introduced, or moved by human activities to a location where they do not naturally occur, are termed invasive, nonnative, noxious, exotic, alien, or nonindigenous” (USDA).

Slide 3


In analyzing how this happened, we’ll see that thousands of people moved to the Midwest looking for opportunities as the logging and mining industries exploded. This resulted in the construction of over 5000 miles of logging railroads and hundreds of miles of tote roads (paths) through the forests (King, 2003). (Image of log jam on St. Croix River)

Slide 4


With the development of the automobile, more roads were built between towns and camps. These roads ultimately became distribution links for invasive species.


Gardening and farming became the impetus for the arrival of new species. Beautifying homesteads with flora and fauna were important to the women, resulting in a demand for gardens that included exotic plants imported from foreign lands. (Price, 1995)

Slide 6


“If you have some flower seeds that can be sent in a letter, think of me, dear Mother and I’ll be very grateful to you for them. I love so much to care for my flowers, especially those that come from our old home” Sophie Bost, in a letter to her mother-in-law in

Switzerland, 1862

Quoted from: Price, Susan Davis. Minnesota Gardens, An

Illustrated History, Afton, MN: Afton Historical Press, 1995, p. 18

Most of our noxious and invasive weeds came from Europe or Asia either accidentally, or as ornamental plants which escaped from home gardens. Most of the problematic species spread by mechanical disturbances such as logging, farming and development, or by natural disturbances such as drought, floods and fire. Characteristics of the soil can change from these disturbances providing opportunities for non-natives more tolerant of those conditions to get a foot-hold before the natives have a chance to regenerate. According to an article from the College of Agriculture and Life Sciences at Cornell University “An estimated 5000 plant species have escaped and now exist in U.S. natural ecosystem, compared with a total of about 17,000 species of native U.S. plants” (Pimentel, et al, 2004).

Slide 7 “The Noxious Weed Law affects growing plants.

Some plants are noxious because they can harm

people, animals, the food we eat, and nature.

County, city, and township officials inspect land

and ask owners to destroy their noxious weeds.

Land owners that refuse to destroy their noxious

weeds can be forced to do so”(MDA).

A plant is deemed to be invasive if it causes negative environmental, economic, or human health effects, which outweigh any beneficial effects. The main differences between a common weed and a noxious weed are the noxious weed's high capacity for destruction, and the tremendous difficulty in controlling or eradicating these invading weeds. They have few or no predators. In addition, land owners who do not remove specific noxious weeds can be forced to do so. This slide gives a current definition according to the MN Department of Agriculture.

Slide 8

Yellow Star Thistle

(Centaurea solstitialis L.)

Cindy Roche @ USDA-NRCS PLANTS Database

J.S. Peterson @ USDA-NRCS PLANTS Database

For example, yellow star thistle is a source of nectar for bee producers. But the displacement of native and other desirable plant species caused by yellow star thistle leads to dramatically decreased forage for wildlife and livestock, which severely disrupts the profitability of associated businesses. These negative effects greatly overshadow the positive effects (NISC, 2006). (NOTE: the yellow star thistle infests nearly 12 million acres in California, Idaho, Oregon, New Jersey, Utah, and Washington and is currently not known in MN-yet. However, It is now on the MN Dept. of Agriculture eradicate list.) More will be discussed about this plant later in the presentation.

Tansy (Tanacetum vulgare) Steve Dewey, Utah State University, Bugwood.org

• The majority of the prohibited noxious weeds prior to

2011 were selected based on agricultural impacts

According to Tony Cortilet, Noxious and Invasive Weed Coordinator at the MN Department of Agriculture, the original classification of noxious weeds was developed mostly due to agricultural impacts from invasive species, thus it provided an avenue for enforcement. For example if a neighbor complained to a county agriculture inspector about an infestation of Tansy or Canada Thistle on a neighbor’s property, that homeowner would most likely be given a notice to eradicate, or control the invasive within a certain time frame. If an effort has not been made by that deadline, the homeowner may be issued a citation and fine, much like a speeding ticket.

Slide 10

Garlic Mustard (Alliaria petiolata) Victoria Nuzzo, Natural Area Consultants, Bugwood.org

Reclassification completed in 2011 • 12 State Prohibited Noxious Weeds

Eradicate List – 3 Species

Control List – 9 Species

• 2 State Restricted Noxious Weeds

• 1 Specially Regulated Plant

Along with agricultural impacts, there are now greater impacts in high quality areas such as woodlands A committee comprised of many agencies that include the Department of Transportation, Nature Conservancy, Pheasants Forever, Minnesota Nursery and Landscape Association, Department of Natural Resources and others, conducted risk assessments on current weeds to reclassify them. (T. Cortilet, personal communication, May 23, 2011). This included a new “Eradicate” list with 3 species, a “Control” list of 9, 2 restricted weeds and 1 specially regulated plant During the remainder of this presentation I will discuss: weed origin, distribution and habitat, ecological impacts, reproduction, uses, toxicity, and control and management.

Slide 11 Eradicate List

• Yellow Starthistle, Centaurea solstitialis L.

• Grecian Foxglove, Digitalis lanata Ehrh.

• Oriental Bittersweet, Celastrus orbicaulatus

Thunb.

Eradicate List – Prohibited noxious weeds that are listed to be eradicated are plants that are not currently known to be present in Minnesota, or are not widely established. These species must be eradicated, meaning all of the above and below ground parts of the plant must be destroyed, as required by Minnesota Statutes, Section 18.78. Ad transportation, propagation, or sale of these plants is allowed. Measures must also be taken to prevent and exclude these species from being introduced into Minnesota. (MDA).

Slide 12

Yellow Starthistle

(Centaurea solstitialis L.)

J.S. Peterson @ USDA-NRCS PLANTS Database

Brother Alfred Brousseau @ USDA-NRCS PLANTS Database

Common Name: Yellow starthistle, St. Barnaby’s thistle, golden starthistle, yellow cockspur, and cotton-tip thistle…related to other knapweeds Historical/Origin: Native to Asia Minor, the Middle East, and south-central Europe, yellow starthistle was probably brought to North America in the mid-1800s as a contaminant of alfalfa seed. By the early 1900s, yellow starthistle had overtaken several wheat fields and pastures and began to spread rapidly. Based on a 2003 estimate, there are approximately 15 million acres of yellow starthistle in 17 western states. (MDA). Distribution/Habitat: Yellow starthistles thrives in sunny, open areas such as grasslands, fields of alfalfa and small grain fields, and roadsides. It can tolerate a wide range of soil moisture conditions. (MDA).

Ecological Impacts: Competes with other species for sunlight, moisture and nutrients-quickly becomes a monoculture. Reproduction/Growth: Annual, (occasionally biennial) reproduces exclusively by seed. Two types of seed are produced. Seeds in the center of the seedhead have white pappi (fluffy hairs) that aid seed movement by wind and animals. Seeds near the seedhead edge do not have pappi. A typical plant can produce 150,000 seeds; Average plant height approx. 1-3 feet; Seeds viable for 10 years in the soil Flower: yellow-with a pointed yellowish spine that is formed at the end of each bract. Together they look like a ring of spikes just below the flowers. Uses and Values: seeds and nectar desirable to birds. Toxicity: Infestations reduce pasture forage quality and the spines can injure the eyes, noses, and mouths of grazing animals. Yellow starthistle is toxic to horses and causes “chewing disease”. Control and Management: Mechanical: Hand pulling is strongly recommended for small infestations and is best done after bolting and up to very early flowering. It is critical to pull plants before they produce viable seed, or bag plants that have already flowered to prevent seed dispersal. Mowing: has produced mixed results. It may be used for moderate infestation levels, but timing is critical, and it is most effective on plants with an upright growth habit. May have to mow 2 X per year for 3 or more years. Grazing: with sheep, goats or cattle are considered partially to moderately effective. Graze sheep or cattle when plants begin to bolt until development of seed heads. Goats may graze it later into the season. Chemical: There are many herbicides available for yellow starthistle Biological: There are five insects approved for biological control plus 1 rust pathogen (MSU Extension) Be on the lookout for yellow starthistle. It may arrive from one of the western states as a contaminant of other plant materials or on vehicles or other equipment. If you suspect that you found yellow starthistle, please report the find to the Minnesota Department of Agriculture. (MDA)

Slide 13

Grecian Foxglove

(Digitalis lanata Ehrh)

USDA-NRCS PLANTS Database

Common Name: Grecian Foxglove, woolly foxglove Historical/Origin: native to central and southern Europe. It was brought to North America as an ornamental then escaped cultivation. Distribution/Habitat: Grecian foxglove thrives in habitats ranging from hot, dry sites to cool, moist, high altitude sites. Reported infestations in Minnesota and Kansas are in open sunny roadsides, residential yards, grasslands, river bluffs, and forest margins (MDA). Ecological Impacts: displaces desirable vegetation such as forage and native plants (MDA). Reproduction/Growth: 2-5 feet tall-perennial plant that forms a

rosette its first year then bolts and sends up a single flowering stem its second and subsequent years. Reproduces by seeds that can be spread by wind, water, vehicles, humans, wildlife, and by moving soil containing seed. Flower: creamy white to pale yellow with brownish-purple venation inside. There are Woolly hairs on the calyx and stem. Note: The common garden foxglove, D. purpurea, can be distinguished by the lack of woolly hairs on the stem and calyx. The leaf shape of garden foxglove is more rounded and the flowers exhibit a wide range of colors. Garden foxglove has not been reported as invasive in Minnesota. Multiple species of Digitalis can hybridize, but no hybrids have been reported in Minnesota. Uses and Values: Beneficial compounds derived from this species provide cardiac medicines. Toxicity: Grecian foxglove is toxic to humans, livestock, and wildlife. Grecian foxglove cut and dried in hay could result in livestock poisoning. All parts of Grecian foxglove are poisonous in both fresh and dried forms. Cardiac glycosides from Grecian foxglove include digoxin and digitoxin and primarily affect cardiovascular, neurologic, and gastrointestinal systems. Ingesting plant parts or absorbing compounds through skin in direct contact with Grecian foxglove may adversely affect humans and other mammals and could be fatal. It is possible that smoke from burning plants may be toxic. Control and Management: Avoid direct contact with this plant to prevent toxin absorption through skin. Wear protective clothing and rubber gloves when handling this species. Mechanical: Hand-pulling is not recommended due to concerns about exposure to toxins and disposal issues. However, repeated hand-pulling (wear protective gloves and clothing) in the spring and fall can control very small populations. Pulling larger populations may result in disturbed areas that are ideal for Grecian foxglove seedlings to germinate. Frequent mowing during the growing season for multiple years may control this species if flowering is prevented. Grecian foxglove can flower and produce seed on a short stem after mowing. So preventing all flowering may be a challenge. Chemical: Annual herbicide applications (in spring and/or fall) can reduce Grecian foxglove populations over time. For all management methods, it is important to monitor several years after treatment due to germination from the Grecian foxglove seedbank (MDA).

Oriental Bittersweet

(Celastrus orbicaulatus Thunb)

Photos: Bugwood .org

Common Name: Oriental bittersweet, Asian bittersweet, climbing spindleberry Historical/Origin: Native to China, Korea, and Japan, Introduced to North America in the mid-1860s as an ornamental. Escaped cultivation and spread throughout the temperate eastern US. Distribution/Habitat: Found in forested areas, field and forest margins, meadows, right-of-ways, fence rows, along waterways and in residential landscapes. Thrives in a range of soil types and light levels from full sun to shade. (MDA). Ecological Impacts: The vines girdle and smother trees and shrubs. The first confirmed Oriental bittersweet infestations in Minnesota were found, reported, and controlled in 2010 by the Minnesota Department of Transportation on their right-of-ways in the Twin Cities area. Tracing back these infestations, they learned that they were planted along fences by persons who thought they had planted American bittersweet. A large infestation of Oriental bittersweet had been confirmed in Winona, Minnesota. It outcompetes and displaces our indigenous American bittersweet to the point that Connecticut now lists the formerly common American bittersweet as a species of concern (MDA). Reproduction/Growth: Oriental bittersweet is a deciduous vine that grows up to 66' long. Reproduces by seeds and rhizomes. The fruits are consumed then dispersed by birds and mammals and ingested seeds have a higher germination rate than seeds that fall to the ground. People move seed by using fruiting stems in flower arrangements. Oriental bittersweet is sometimes mistakenly labeled as American bittersweet then sold and planted. Flower: Flowering occurs in the spring and flowers are arranged in clusters of 2-7 at the leaf axils. Fruits are round and change in color from green to bright red with a yellow capsule as they mature. Typical female plants can produce up to 370 fruits which ripen in the fall. Uses and Values: Ornamental. Toxicity: none known Control and Management: Do not collect and use the fruiting stems for ornamental purposes. Remove all infestations from your property. Bag or burn all fruit for disposal. For all management options, infested sites will need to be monitored and treated repeatedly until the seedbanks are depleted. Mechanical: Regular, weekly mowing will control Oriental bittersweet, but less frequent mowing may result in suckering from the roots (MDA). Chemical: Foliar or cut stump herbicide applications can be effective.

Controlled List

1. Leafy Spurge Euphorbia esula L.

2. Canada Thistle Cirsium arvense L. Scop.

3. Musk Thistle Carduus nutans L.

4. Plumeless Thistle Carduus acanthoides L.

5. Garlic Mustard Alliaria petiolata (Bieb.) EXT

6. Purple Loosestrife Lythrum salicaria, virgatum L.

7. Wild Parsnip, Pastinaca sativa L.

8. Common Tansy Tanacetum vulgare L.

9. Spotted Knapweed, spotted Centaurea

maculosa Lam.

Controlled List - Species on this list must be controlled, meaning efforts must be made to destroy all propagating parts and prevent seed maturation and dispersal, thereby reducing established populations and preventing reproduction and spread as required by Minnesota Statutes, Section 18.78. Additionally, transportation, propagation, or sale of these plants is prohibited (MDA).

Slide 16 Leafy Spurge (Euphorbia esula)

Minnesota Department of Agriculture

University of Minnesota Extension

(http://www.dnr.state.mn.us/invasives/terrestrialplants/herbaceous/leafyspurge.html) Common Name: Leafy Spurge (Can anyone name another common seasonal house plant that is from the same family? Answer: Poinsettia) Historical/Origin: Native to Europe and Asia; seed impurity in the early 1800s. First recorded from Massachusetts in 1827, and reached North Dakota within about 80 years. Distribution/Habitat: Tolerant of a wide range of habitats, dry to moist sunny & semi-shade. Most aggressive in dry soil conditions Ecological Impacts: displaces native vegetation; very aggressive invader; can completely overtake large areas of open land. Reproduction/Growth: Perennial; 2- 3 1/2'; Seeds disperse explosively from a seed capsule up to 15‘ from the parent plant. high germination rate seeds viable in the soil for up to 7 years Stems, flowers, and leaves emit a white milky sap called latex Massive network of small lateral roots near the soil surface and deep, penetrating taproots that have been known to extend to depths of 15 ft. This ability to maintain high root reserves permits the plant to recover quickly from physical and most chemical damage (USDA). Flower: yellow-green bracts bloom from June into fall. Control and Management: Mechanical and Chemical: Prescribed burning in conjunction with repeated treatment with broadleaf weed and broad-spectrum systemic herbicide. If left uncontrolled for a single year, leafy spurge can re-infest rapidly resulting in the need for multiple treatments every year for several years. Biological: Root-boring beetle, four root-mining beetles, shoot-tip gall midge; grazing goats or sheep but goats were better (Cornett, Bauman and Breyfogle, 2006) FAST FACT: Leafy spurge costs ranchers in ND, SD, MT, WY more than $144 million a year. (Bangsund and Leistritz, 1991)

Canada Thistle (Circisum arvense)

Al Schneider @ USDA-NRCS PLANTS Database

University of Minnesota ExtensionUniversity of Minnesota ExtensionUniversity of Minnesota Extension

(http://www.dnr.state.mn.us/invasives/terrestrialplants/herbaceous/canadathistle.html)

Common Name: Californian thistle, Canadian thistle, creeping thistle, field thistle, corn thistle, perennial thistle, field thistle--- sunflower family (Asteraceae) Historical/Origin: early 1600s; by 1954 noxious weed in 43 states & in Canada Distribution/Habitat: disturbed areas Ecological Impacts: major agricultural pest; costs tens of millions of dollars in direct crop losses annually and additional millions in control costs. Reproduction/Growth: Herbaceous perennial plant that grows 2 - 5' tall Tufted seeds; viable in the soil for over 20 years [RESEARCH]-”Wind dispersal is not as significant a factor in the movement of Canada thistle seeds as was commonly thought. Most viable seeds fall to the ground nearby without pappi attached” (Becker, Haar, et. al., 2008). This results in circular patches or colonies. Further, many seeds produced by Canada thistle stands are either nonviable or of questionable viability. Also spreads vegetatively through horizontal roots which can stretch 10 -12' in one season 75% of a Canada thistle plant is underground flowers & stems do not have spines or prickles, unlike bull or musk thistle Flower: between June and September. Uses and Values: provides nectar for bees and butterflies Control and Management: “Strategies should focus less on wind dispersal and more on controlling the stand of thistle and the seedbank close to the parent plants” (Becker, Haar, et. al., 2008). (See management for all thistles on upcoming slide)

Slide 18 Canada Thistle (Circisum arvense)


C. arvense plant with multiple inflorescence disease

http://www.bspp.org.uk/publications/new-disease-reports/ndr.php?id=010046

Canada Thistle has been known to get a phytoplasma disease similar to what is commonly known as aster yellows. This disease is transferred by a microscopic insect called eriophyid mites. In the field the disease persists for years, increasing slowly around the original infection focus. Infected plants senesce prematurely, inhibiting both seed production and rhizome propagation, which markedly reduces the C. arvense population. (http://www.bspp.org.uk/publications/new-disease-reports/ndr.php?id=010046)

Musk Thistle (Carduus nutans)


(http://www.dnr.state.mn.us/invasives/terrestrialplants/herbaceous/muskthistle.html)

Common Name: Musk or Nodding Thistle Historical/Origin: early 1800s, A native of western Europe Distribution/Habitat: disturbed areas-It generally does not pose a threat to high quality areas. Ecological Impacts: prolific seed producer. A robust plant may produce 100 or more flowering heads One plant can set up to 20,000 seeds. However, only one-third of the seeds are viable. Most seed is dispersed within the immediate vicinity of the parent plant. This leads to a clumped pattern of seedling development Reproduction/Growth: Herbaceous biennial plant, fibrous taproot, 1 1/2 - 6' tall Flower: bloom from June through July - Flowerheads droop to a 90 degree angle from the stem when mature-hence name “Nodding Thistle”. Uses and Values: nectar for birds and butterflies Toxicity: nonpalatable to grazing animals Control and Management: (See management for all thistles on upcoming slide)

Slide 20

Plumeless Thistle

(Carduus acanthoides)

R.A. Howard @ USDA-NRCS PLANTS Database

(http://dnr.wi.gov/invasives/fact/thistles_plum.htm)

Common Name: Plumeless Thistle, Bristly thistle Historical/Origin: Southern Europe and western Asia; first discovered in the United States in Camden, New Jersey in 1878 (http://www.invasive.org/species/subject.cfm?sub=3400). Distribution/Habitat: disturbed areas Ecological Impacts: an aggressive weed and is similar to the closely related musk thistle; Reproduction/Growth: Biennial; usually 3-4 ft tall; spiny wings; Stout fleshy taproot can penetrate soil several feet. These species readily hybridize with Musk Thistle, and plants with intermediate characteristics may be found where their ranges overlap. Flower: Purple, rarely white or yellow; blooms June-August Uses and Values: Food for butterflies & songbirds. Toxicity: unpalatable to livestock. Control and Management: ALL THISTLES - An integrated 3-5 year weed control program that combines chemical, cultural (such as crop rotation or grass competition), mechanical and biological methods is most likely to be successful. Mechanical Control: Eliminating seed production is the most effective. Thistles mowed in bud or early bloom stage will produce new branches from buds in the axils of the basal leaves. However, close mowing or cutting twice per season will usually prevent seed production. This can be done at any time during the growing season, although cutting is easier when the thistles are smaller. Mowing once flowering has begun may result in the spread of viable seeds with the mower. Chemical Control: Most effective in the fall and when plants are in the rosette stage and least effective when thistles are flowering. Can use broadleaf weed or broad-spectrum systemic herbicide-based on label recommendations Biological Control: Two exotic weevils, the flower head weevil

(Rhinocyllus conicus) and the rosette weevil (Trichosirocalus horridus) have been introduced in several states, and appear to be effective biological control agents that limit populations of musk thistle. They are non-specific however, and may affect native thistles.

Slide 21 Garlic Mustard (Alliaria petiolata)

G.A. Cooper @ USDA-NRCS PLANTS

Database

Elaine Haug @ USDA-NRCS

PLANTS Database

Common Name: Garlic mustard Historical/Origin: Garlic mustard was first recorded in the United States about 1868 in Long Island, New York. It was likely introduced by settlers for food or medicinal purposes. It was first identified in WI in 1938 before being added to the MN Prohibited Noxious Weed List (Sheehan, 2007). Distribution/Habitat: Garlic mustard is found in disturbed areas and in high quality woodlands, upland and floodplain forests. It is also shade tolerant (Blossy, 2002). Seeds can travel many meters from the parent plant, most likely aided by wildlife or humans. Garlic Mustard occurs in 27 midwestern and northeastern states, and in Canada. Ecological Impacts: Garlic mustard out-competes many native wildflowers including spring beauty, wild ginger, bloodroot, Dutchman's breeches, hepatica, toothworts, and trilliums. Infestation can affect wildlife diversity that relies on the natives for food. “Invaded sites undergo a decline of native herbaceous cover within 10 years” (MN DNR). “A recent study indicates that garlic mustard produces a phytochemical that kills or inhibits mycorrhizal fungi on which many woody plants depend…there is speculation that this could cause profound changes in plant species composition over time (Blossy, 2002). Reproduction/Growth: Herbaceous biennial plant-reproduces by seeds. Each plant can produce from 66-356 seeds, with a robust plant capable of producing as many as 7,900 seeds; can remain viable in the soil for 3-5 years (Blossy, 2002). Leaves and stems smell like onion or garlic when crushed. Their white, slender taproot is "S"-shaped at the top. Flower: White, small and numerous, with four separate petals. Each plant has one or two flowering stems on second year plants. Uses and Values: Has been used as a food additive, flavoring, medicines, and as a potherb and a source of Vitamin C (Blossy, 2002). Control and Management: Mechanical - Pulling in areas of light infestations during the second year, as opposed to the first year while in the rosette stage; mowing at ground level or prescribed burning; Chemical - Spot application of a broad-spectrum systemic herbicide in early spring or late fall when native plants are dormant (MN DNR). Biocontrols are being tested; there are 69 insects and 7 fungi associated with garlic mustard in Europe, but none found to be host specific. There appears to be some biocontrol potential with a couple of weevils and a flea beetle, but there is still research needing to be done (Sheehan, 2007).

Purple Loosestrife (Lythrum salicaria)

Gary A. Monroe @ USDA-NRCS PLANTS Database

Minnesota Department of Natural

Resources

(http://www.dnr.state.mn.us/invasives/aquaticplants/purpleloosestrife/index.html) Common Name: Purple Loosestrife Historical/Origin: Europe and Asia. East coast seeds present in the ballast holds of European ships-later distributed as an ornamental in1800s by settlers for their flower gardens Distribution/Habitat: Found in 48 states and all Canadian border provinces and costs 45 million annually in control and forage loss (Pimentel, et al, 2004). 2,000 purple loosestrife infestations recorded in 68 of Minnesota's 87 counties. (70%) are lakes, rivers, or wetlands. 58,000 acres infested with purple loosestrife. Ecological Impacts: overpowers cattails and other wetland plants Not suitable as cover, food, or nesting sites for a wide range of native wetland animals including ducks, geese, rails, bitterns, muskrats, frogs, toads, and turtles. Reproduction/Growth: 2-7’ tall; A single stalk can produce from 100,000 to 300,000 seeds per year. Mature plants with up to 50 shoots can produce more than two million seeds a year. Seeds remain viable in the soil for many years. Control and Management: Mechanical: Digging & hand pulling: Pulling by hand is easiest in late June, July and early August when plants are young (up to two years) or when in sand. Easy to recognize when in flower and best to remove before it has gone to seed. Composting is not advised. Chemical: broad-spectrum systemic herbicide labeled specifically for aquatic systems Biocontrol: ( Continued on Next Slide)

Slide 23 Loosestrife-biocontrol

Before biocontrol insects

released: Purple loosestrife

infested wetland near Winona,

MN; 1997.

After biocontrol insects released: Defoliated purple loosestrife wetland near Winona, MN; 2000.

Photos: Minnesota Department of Natural Resources

(http://www.dnr.state.mn.us/invasives/aquaticplants/purpleloosestrife/index.html) Biological: Prior to any introduction of a biological control agent, intensive testing is conducted to ensure that a safe and effective agent is selected; Testing began in Europe and was completed in North America between 1987 and 1991. Out of more than 100 insects that feed on loosestrife, four species of beetles were introduced into Minnesota; two leaf-feeding beetles, one root-boring weevil and one flower-feeding weevil. More than 8 million leaf-feeding beetles have been reared and released on more than 700 purple loosestrife infestations statewide. Recent assessments demonstrate that the leaf-feeding beetle introductions have caused severe defoliation of loosestrife populations on over 20% of sites visited.

Wild Parsnip (Pastinaca sativa)

John Cardina, The Ohio State University,

Bugwood.org

Kitty Kohout, Wisconsin State

Herbarium

(http://www.dnr.state.mn.us/invasives/terrestrialplants/herbaceous/wildparsnip.html) Common Name: Wild Parsnip Historical/Origin: Native of Europe and Asia; grown as root vegetable; escaped from cultivation, now common throughout the U.S. Distribution/Habitat: Primarily a problem in southeastern Minnesota in prairies and oak openings. Ecological Impacts: moves rapidly into disturbed habitats Reproduction/Growth: Monocarpic perennial herbaceous plant (plant spends one or more years in rosette stage, blooms under favorable conditions, and then dies) Seeds: viable in the soil for 4 years. Flower: appearance is somewhat like the ornamental but also invasive Queen Anne’s Lace. Uses and Values: edible taproot Toxicity: Warning - Avoid skin contact with the toxic sap of the plant tissue by wearing gloves, long sleeves and long pants. The juice of wild parsnip in contact with skin in the presence of sunlight can cause a rash and blistering and discoloration of the skin (phytophotodermatitis). Sunburn in animals occurs after ingestion. Control and Management: Mechanical: Do nothing in healthy prairies, natives can sometimes outcompete the parsnip; Hand pulling and removing of plants; Cut the plant below the root crown before seeds set, and remove the cut plant; Mow or cut the base of the flowering stem and remove Chemical: Can use broadleaf weed or broad-spectrum systemic herbicide-based on label recommendations. If after a prescribed burn, since parsnip is one of the first plants to green up, that is also a good time for chemical application. NOTE: According to Tony Cortilet from the Minnesota Department of Agriculture, this weed will most likely be added to one of the noxious weeds lists upon completion of a risk assessment underway to determine classification. (T. Cortilet, MDA, Personal Communication, December 21, 2009).

Slide 25 Tansy (Tanacetum vulgare)

Lindsey Koepke @ USDA-NRCS PLANTS Database

MN Department of Agriculture

Common Name: Tansy aka: Bitter Buttons, Cow Bitter, Mugwort or Golden Buttons (Currently on the MN Department of Agriculture’s Secondary Noxious Weed List and is a prohibited noxious weed in four Minnesota counties). Historical/Origin: 1600s from Europe and Asia Distribution/Habitat: Disturbed areas. Bigger problem in Northern MN due to cold tolerance of 30 below zero. Prohibited in Roseau, Itasca, Cass & Koochiching Counties Ecological Impacts: Can grow densely along ditches and streams and restrict water flow-outcompetes native plants, grasses and forbs. (http://www.dnr.state.mn.us/invasives/terrestrialplants/herbaceous/commontansy.html)

Reproduction/Growth: Herbaceous perennial, grows 3’-6’ tall; spreads primarily by seeds and rhizomes Flower: Blooms July-October Uses and Values: originally as an ornamental (still sold in some areas) and for medicinal purposes. It was used to treat external and internal parasites. Heavy consumption could be dangerous because the plant’s volatile oil contains thujone, a substance that can cause convulsions and miscarriages (WI DNR). Toxicity: toxic to humans and many animals when ingested-however doesn’t seem to bother sheep and goats Control and Management: Mechanical Control: digging; cut flower heads before seed production; burning Chemical Control: Can use broadleaf weed or broad-spectrum systemic herbicide-based on label recommendations Biological: A root-feeding flea beetle is currently being tested for host specificity (M. Chandler, MDA, personal communication, December 16,

2009) Slide 26

Spotted Knapweed

(Centaurea stoebe L.)

University of Missouri Extension

Elaine Haug @ USDA-NRCS PLANTS Database

Common Name: Spotted Knapweed Historical/Origin: Native to Europe and Asia, spotted knapweed was accidentally introduced to North America in the late 1800s. Distribution/Habitat: common weed in Minnesota of roadsides and pastures with dry, sandy soil Ecological Impacts: can be spread by wind, water, wildlife, vehicles, contaminated hay, farm machinery, gravel distribution, logging equipment, and road construction; displaces desirable vegetation and can take over large areas; is now found in most states Reproduction/Growth: Reproduces by seed-viable 7 years; biennial or short lived perennial; approximately 2-3 feet tall Flower: thistle-like pinkish purple flowers-July-Sep Uses and Values: none Toxicity: produces a chemical that is toxic to other plants; Wear long sleeves and gloves, can be a skin irritant to some people. Control and Management: Biological: In Minnesota, the predominant biological control agents used include seedhead flies, seedhead weevils, and root boring weevils. Mechanical-Early detection and pulling; Mowing as needed so plants cannot go to seed Prescribed burning, only very hot burns are effective which may also damage native plants Chemical-Apply selective herbicide clopyralid during bud growth in early June for best results

Restricted

• Common Buckthorn (Rhamnus cathartica)

• Glossy Buckthorn (Frangula alnus)

Restricted Noxious Weeds Restricted noxious weeds are plants that are widely distributed in Minnesota and are detrimental to human or animal health, the environment, public roads, crops, livestock or other property, but whose only feasible means of control is to prevent their spread by prohibiting the importation, sale, and transportation of their propagating parts in the state except as allowed by Minnesota Statutes, Section 18.82. Plants designated as Restricted Noxious Weeds may be reclassified if effective means of control are developed. (MDA)

Slide 28

Common Buckthorn (Rhamnus cathartica)

Glossy Buckthorn (Frangula alnus)

Gil Wojciech, Polish Forest Research Institute,

Bugwood.org

Wisconsin Department of Natural Resources

(http://www.dnr.state.mn.us/invasives/terrestrialplants/woody/buckthorn/index.html) Common Name: Common buckthorn (Rhamnus cathartica); Glossy buckthorn (Frangula alnus) Historical/Origin: Europe in the mid-1800s as a very popular hedging material. The nursery industry stopped selling it in the 1980s, but many buckthorn hedges may still be found in older neighborhoods throughout Minnesota. Distribution/Habitat: Glossy buckthorn typically invades wetlands including swamps, bogs, ferns and wet meadows but also occurs in upland habitats such as woodland edges, old fields and roadsides. Common buckthorn is primarily an invader of upland sites including open woods, woodland edges, prairies and open fields. Both species are capable of growing in full sun as well as heavily shaded areas. Ecological Impacts: Out-competes native plants for nutrients, light, and moisture Degrades wildlife habitat Serves as host to other pests, such as the fungus, crown rust of oats and soybean aphid Reproduction/Growth: 25’ Common buckthorn is a dioecious plant, meaning that each plant produces only male or female flowers; fruiting trees are always female. Flower: Common buckthorn flowers from May through June and fruit ripens August through September; another distinction for common buckthorn is that the berries remain on the plant over winter. Glossy buckthorn blooms from late May until the first frost and produces fruit from early July through September. Various stages of ripening can be found on the same branch at the same time. Uses and Values: Hedges-wood is valued by woodworkers Toxicity: fruit is eaten by birds and mice and is known to produce a severe laxative effect, helping distribute seeds Control and Management: Mechanical: Pulling or digging when young; Prescribed burns only where conducive and by professionals Chemical: During the growing season, cut stems off near ground level and brush the freshly cut wound with a concentrated glyphosate Biological: According to Monika Chandler at the MN Dept. of Ag., this one is very difficult to control biologically because it is woody and not herbaceous. They are testing some beetles but, it’s not

too promising yet (M. Chandler, MDA, Personal Communication, December 16, 2009)

Slide 29 Specially Regulated Plants

• Poison Ivy (Toxicodendron rydbergii)

Specially Regulated Plants Specially regulated plants are plants that may be native species or have demonstrated economic value, but also have the potential to cause harm in non-controlled environments. Plants designated as specially regulated have been determined to pose ecological, economical, or human or animal health concerns. Plant specific management plans and or rules that define the use and management requirements for these plants will be developed by the Minnesota Department of Agriculture for each plant designated as specially regulated. Measures must also be taken to minimize the potential for harm caused by these plants. (MDA)

lide 30 Poison Ivy (Toxicodendron rydbergii)

Jeff McMillian @ USDA-NRCS PLANTS Database James H. Miller @ USDA-NRCS PLANTS Database

Erica Asai @ USDA-NRCS

PLANTS Database

Common Name: Poison Ivy -Leaves of 3, let it be Historical/Origin: Native Distribution/Habitat: A woody vining type of ground cover that can grow several feet. It is found mostly in uncultivated sites such as woodland areas and can grow several feet in the air with support on trees, fences and shrubs. Ecological Impacts: It causes dermatitis in approximately 85 percent of the population Reproduction/Growth: Perennial; reproduces by rhizomes and seeds Flower: Yellowish-green, May-June; Uses and Values: Seeds & fruits provide food for upland game birds and wild turkeys; Deer also browse the leaves and twigs. Toxicity: urushiol, (pronounced oo-roo-shee-ohl) is the oily compound that generates the allergic reaction; the highest concentration is produced in the plant in the spring and summer. Urushiol oil residual can last 1-5 years on dead plants and tools. Animals are seldom susceptible. Cleansing with soap, rubbing alcohol or mineral spirits may not stop the initial outbreak of the rash if more than 10 minutes has elapsed, but it can help prevent further spread. [Change Slides] ANIMATION SLIDE: all parts of plants including roots are toxic as this gentleman found out while digging a hole in the ground Control and Management: Mechanical: manual removal - NOTE: wear rubber, not cotton gloves and knee high rubber boots. Wash tools in sudsy water and wipe down with rubbing alcohol or mineral spirits Chemical: brush killer or broad-spectrum systemic herbicide-based on label recommendations DONOT BURN as the fumes are also toxic-it is not recommended to compost either (MN Dept. of Ag.) (http://poisonivy.aesir.com/view/welcome.html)

County Noxious Weeds

Contact your County Agricultural inspector or

County Designated Employee for more

information.

County Noxious Weeds County noxious weeds are plants that are designated by individual county boards to be prohibited within the county’s jurisdiction and must be approved by the Commissioner of Agriculture, in consultation with the Noxious Weed Advisory Committee. Each county board must annually submit their proposed County Noxious Weed List to the Minnesota Department of Agriculture for review. Approved County Noxious Weeds shall also be posted with the county’s general weed notice prior to May 15th each year. Counties are solely responsible for developing County Noxious Weed lists and their enforcement. Contact your County Agricultural Inspector or County Designated Employee for more information.

Slide 32

Cooperative Weed Management Areas

For large infestations there is help. There are Cooperative Weed Management Areas (CWMA’s) where partnerships have developed with federal, state and local government agencies along with tribes, individual landowners and various other interested groups that manage noxious weeds or invasive plants in a defined area. Applicant Eligibility: Soil and Water Conservation Districts (SWCDs) are the eligible grant applicants for this program. Other organizations may consider applying in partnership with SWCDs to help develop and run the Cooperative Weed Management Area. Benefits of the Program ■Development of strong partnerships based on cooperation among agencies, landowners and other interested partners to control invasive species. ■The creation of long-term and sustainable Cooperative Weed Management Areas. ■The removal of invasive plant species and the restoration/reconstruction of native communities. ■Funding to supplement other invasive species control efforts. The Cooperative Weed Management Area grant program focuses on the development of restoration of natural and conservation lands through invasive species removal and replanting with local species. WEBSITE: http://www.bwsr.state.mn.us/grantscostshare/CWMA.html

Slide 33 Summary

Summary: Being able to identify Noxious and Invasive plants is the first step in long-term management. Homeowners need to be aware that they are responsible for eradication or control of noxious weeds on their properties. Once the weeds have been identified, it is important to learn which ones are prohibited in their county and then take efforts to prevent further spread. As you have learned from this presentation, many of these plants are very prolific. If one person removes one mature loosestrife plant, by doing so, this could potentially prevent up to one million seeds from spreading. Imagine if you removed 30 plants. For further information, the handouts have web links for many excellent resources. Please complete the evaluation before

exiting. [Optional for presenter] Encourage participants to leave an email address for a follow-up survey to determine if the participants applied their learning from this presentation into action. It is recommended to send the survey 2-3 months from the presentation date.

Slide 34 Questions?

Thank you

QUESTIONS?

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