city council agenda submission december 11, 2018

CITY COUNCIL AGENDA SUBMISSION December 11, 2018

Agenda Item:

Missouri Invasive Species Task Force

Description:

The multi-agency Missouri Invasive Species Task Force (MoIP) is a state-wide initiative to increase public awareness and bolster efforts to control invasive species. The MoIP has created a pledge for public, private and non-profit agencies as well as private property owners to join their efforts. The Pledge is a commitment for an agency to actively remove invasive species; cease planting invasive species and use native plantings whenever possible; and build partnerships and collaborate with other groups to assist in outreach, education and joint efforts. The commitments outlined in the Pledge are consistent with current City practices and the adopted Parks Master Vision Plan. Recommended Action:

Motion to approve the City of Olivette taking the Pledge to stop the spread of invasive plant

species.

Attachments:

Parks & Recreation Commission Agenda Report from November 28, 2018

Funding Request:

None

Submitted by:

Beverly Tucker Knight DEPARTMENT HEAD

ATTACHMENT 1

City of Olivette

Parks & Recreation Commission

AGENDA ITEM REPORT

November 28, 2017

ITEM NO. 7

ITEM:

Missouri Invasive Species Task Force

COMMENTS:

Recommendation to pledge to stop the spread of invasive plant species.

Invasive species in Missouri have a negative economic impact on forestry and wildlife

management, farming, and tourism each year. Many government and non-profit agencies are

dedicated to stopping invasive species, both plant and animal, from spreading. A new state-wide

initiative is bringing all of the disparate groups together to increase public awareness and

improve success rates.

Missouri Invasive Species Task Force (MoIP)

Formed in 2017, the Missouri Invasive Species Task Force (MoIP) is a multi-agency, multi-

industry networking and advocacy group to bolster statewide efforts to identify and

control the invasive plant species that severely impact native biodiversity.

MoIP is comprised of representatives from the Missouri Department of Conservation; National

Forest Service; Missouri Department of Natural Resources, Missouri Botanical Garden;

University of Missouri, Missouri Department of Transportation; Missouri Department of

Agriculture, Missouri Forestry Council; U.S. Fish & Wildlife Service; Kansas City Native Plant

Initiative; Missouri Consulting Foresters Association; Missouri Walnut Council; Natural

Resources Conservation Service; Grow Native!; Missouri Prairie Foundation; commercial

nursery industry representatives; and private citizens.

The MoIP mission is “to identify and control the invasive plant species that severely impact

native biodiversity”. Its goals are:

• Develop a list of top invasive plant species and their assessment scores so we can focus

efforts.

• Become a portal for invasive management in the state. And contribute to regional and

national efforts (such as the Midwest Invasive Plant Network).

• Develop recommendations to influence policy and strategies to influence action to

manage invasive species within Missouri and the Midwest region.

• Track and stop continued distribution of known and future exotic invasive plants.

• Reach new audiences.

• Find sustained, stable funding.

• Determine geographic priority areas for invasive control, including education

opportunities (high public use areas) and native biodiversity.

http://moinvasives.org/

http://moinvasives.org/

• Focus our efforts in a unified front to impact things on the ground; priority geographic

areas; agency cooperation and coordination.

The Task Force offers many free resources including identification and management guides,

support organizations, reporting tools, species specific identification and management practices,

educational videos, academic studies, native plant resources, removal techniques, management

practices, and online access to current field study cases.

Invasive Species Impact

Each year, invasive species have over a $120 billion impact on the U.S. Economy.1

It can be difficult for people to understand how clearing just one City park or one individual

homeowner’s property of bush honeysuckle can make any sort of difference in stopping the

spread of an invasive species. Each plant produces hundreds or even thousands of seeds each

year. These seeds are eaten by birds and then spread across the neighborhood and the larger

region as soon as the bird eliminates on its next couple of stops. Taking the seeds of one or two

plants out of production has an immediate and significant impact. Replacing the cleared bush

honeysuckle with native plants improves the diet of native birds which in turn increases their

survival rate. Native plants also improve the habitat for native mammals, reptiles, insects,

amphibians and even lichen and mosses.

From Memorial Day to Labor Day in 2015, the Montana Department of Fish, Wildlife and Parks

(FWP), examined and collected the home zip codes of 36,997 watercraft at 18 inspection stations

across the state. Some of the stations were mobile and some didn’t operate every day of the

week, so this total doesn’t capture every boat brought into Montana that summer, but it does

provide an excellent illustration how quickly an invasive species can spread purely by accident.

Of the 36,997 boats examined, 227 showed visible signs of contamination by an invasive plant,

animal or water.

The chart below shows the home zip code of all 36, 997 watercraft inspected in Montana in

2015.2

The Pledge

The Pledge helps further several of the Task Force goals at once:

• Become a portal for invasive management in the state. And contribute to regional and

national efforts (such as the Midwest Invasive Plant Network).

• Develop recommendations to influence policy and strategies to influence action to

manage invasive species within Missouri and the Midwest region

• Reach new audiences.

• Focus our efforts in a unified front to impact things on the ground; priority geographic

areas; agency cooperation and coordination.

When an agency takes the Pledge, it lets the stakeholders of a campus, business, community, or

other entity who may be concerned with invasive plants on that property know that the entity, by

taking the pledge, has committed to developing a plan and dedicating resources to the control of

invasive plant species. Second, it helps stakeholders understand that controlling invasive plants

on that property will take time. Additionally, when a community or other entity lets its

stakeholders know it has signed the pledge, it provides an opportunity for stakeholders to get

involved in the effort.

“Invasive plants are serious threats to Missouri’s native ecosystems, as well as many

native plants and animals, the built environment, and many facets of the state’s economy,

including cattle production, the timber industry, and many aspects of outdoor recreation,

including fishing and hunting industries,” said Carol Davit, Executive Director of the

Missouri Prairie Foundation and current MoIP Chair. “Missouri will control invasive

species only with the concerted efforts of many entities, including private citizens

working together. Our state is a long-time, nationwide leader in natural resource

conservation, and by leading in invasive plant control as well, we can further safeguard

Missouri’s habitats, fish, wildlife, and other cherished aspects of our natural heritage.”

Agencies may sign the Pledge online via a Google form. MoIP can also provide a pledge

document suitable for signing ceremonies and framing.

Olivette in Bloom will discuss signing on to the Pledge at their board meeting on Monday,

November 26, 2018.

Pledge to Stop the Spread of Invasive Plant Species

An invasive plant is defined as a species whose introduction to Missouri causes

economic or environmental harm. In most cases, invasive plants evolved in other parts

of the world and were introduced to Missouri by people. It is also important to

understand that some native plants, usually via land disturbances by people, can exhibit

aggressive qualities similar to invasive plants and may also need to be controlled. An

example is eastern red cedar, which has spread beyond its original habitat and

abundance in Missouri due to landscape changes and suppression of fire.

Invasive plants pose serious threats to Missouri’s native ecosystems, as well as many

native plants and animals, the built environment, and many facets of the state’s

economy, including cattle production, the timber industry, and many aspects of outdoor

recreation, including fishing and hunting industries.

We/I, the undersigned representative(s) of [please submit your information below], are

committed to the identification and control of invasive plants on land under our

jurisdiction. We pledge to plan and budget funds and/or human resources for the

removal and ongoing management of invasive species in order to reduce the spread and

impact of invasive plants and to help native species thrive. We understand that control

efforts may take years of work, and are committed to this long-term process.

We also pledge to cease planting any species or cultivar of species listed on the

current edition of the MoIP Missouri invasive plant master listing (other than for

controlled research purposes), and to incorporate plants native to Missouri when

practical.

By taking the MoIP Invasive Plant Management Pledge, we signal our resolve to

control invasive species and encourage other entities to follow suit. With many entities

taking action to control invasive species on land within their own jurisdictions and by

collaborating across property boundaries, together, we can positively influence the

perpetuation of native ecosystems, native wildlife, economies based on wise land use,

and the communities in which we live, for the benefit of all.

1. David Pimentel, Rodolfo Zuniga, Doug Morrison: Ecological Economics, Vol 52, Issue

3, Feb 15, 2005, pgs 273-288 2. 2015 Watercraft Inspection Annual Report; Montana Fish, Wildlife & Parks

ATTACHMENT:

1. MoIP Fact Sheet 06.19.2017

2. Invasives Brochure – Midwest Invasive Plant Network

3. General Guidelines for Controlling Invasive Plants - MoIP

PRESENTED BY:

Beverly Tucker Knight, Parks and Recreation Director

https://www.sciencedirect.com/science/article/pii/S0921800904003027#!



conservation | agriculture | botanical science | ecological services | production horticulture | landscape services | design | arboriculture | retail horticulture | municipal government | elected leadership |

transportation / public and private landowners and land managers

The Missouri Invasive Plant Task Force is housed and administered by Grow Native!, a native plant education and marketing program of the Missouri Prairie Foundation. The purpose of the task force—working as a united, supportive front—is to review, discuss, and recommend educational and regulatory action related to managing known and potential non-native invasive plant species that negatively impact natural communities and built landscapes in Missouri and elsewhere in the lower Midwest. The vision is to ultimately transition this Task Force to a permanent Missouri Invasive Plant Council.

TASK FORCE REPRESENTATION:

• Agriculture• Arboriculture/Urban Forestry• Botanical Science• Conservation Agencies• Ecological Restoration

Services• Education

• Land Planning and Design• Landscape Services• Military Land Management• Municipal Government• Production Horticulture• Retail Horticulture• Transportation

Immediate goals of the Task Force, which meets quarterly, include• developing a comprehensive list of invasive plant species, specifically

impacting lower Midwest landscapes, and their assessment scores• serving as a portal for management of invasive plants in the lower Midwest• reaching new audiences to build public awareness and alliances with

landowners and industries• determining priority areas for invasive control• developing recommendations to hasten action to control invasive plants

Missouri Invasive Plant Task Force – www.moinvasives.orgMissouri Prairie Foundation • PO Box 200 • Columbia MO 65205 • 888-843-6739

[email protected] • www.moprairie.org • www.grownative.org

http://moinvasives.org

http://www.grownative.org

Why Should I CareAbout

Invasive Plants?

HOW INVASIVE PLANTS IMPACTHUNTING, FISHING, BOATING,GARDENING, HIKING, BIKING,

HORSEBACK RIDING, ANDOTHER RECREATIONAL ACTIVITIES

IN THE MIDWEST

Invasive plants, if left unchecked, will limit many uses on lands now and for future generations.

Invasive plants can harm the natural heritage of our wetlands, prai-ries, forests, lakes, and rivers.

Invasive plants can decrease your ability to enjoy hunting, fishing, mushroom collecting, bird watching, and other recreational pursuits.

The longer we wait, the more expensive it will be to control invasive plants.

Invasive plants are spreading on almost all private and public lands in the Midwest.

SO WHY SHOULD YOU

You can be a part of the solution by being aware of invasive plants and taking action to prevent their spread.

To learn more, please read on!

Kudzu taking over a forest in Illinois

Cover photo by Christopher Jordan

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An invasive plant is defined as a plant that is not native and has negative effects on our economy, environment, or human health. Not all plants introduced from other places are harmful. The term “invasive” is reserved for the most aggressive plant species that grow and reproduce rapidly, causing major changes to the areas where they become established.

The Midwest Invasive Plant Network (MIPN) was formed to help reduce the impact of invasive plant species in the Midwest. This network is composed of people from federal, state, and local govern-ments, universities, industry, non-profit organizations, and the gen-eral public, who are concerned about invasive plants. Together we are working to address the threats of invasive plants through prevention, early detection and rapid response, control and management, research, and education.

Invasive plants are a major threat on a national scale. Across the U.S., invasive plants are estimated to occur on 7 million acres of our national park lands, and at least 1.5 million acres are severely infested. In addi-tion to federal lands, state and private lands are also plagued with in-vasive plants and may have even higher infestation rates. This problem is an expensive one. The economic cost of invasive plants is estimated at more than $34 billion per year, and the costs continue to grow. Now is the time to act to reduce the threat of invasive plants in our region.

Purple loosestrife invading a stream bank

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First of all, what is an invasive plant?

What is the Midwest Invasive Plant Network?Le

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If I am a logger or forester, why should I care?

Invasive plants can greatly impact the health and regeneration of forest lands. For example, garlic mustard can rapidly spread into the un-derstory of hardwood stands, and has been documented to suppress other understory plants, which may reduce tree seedling establish-ment. Japanese barberry, an invasive shrub, not only crowds out other plants, but also alters soil conditions to its benefit. Deer avoid eating this spiny shrub, which means they browse more on native trees, slow-ing the growth of seedlings or even killing them.

Dense thickets of Japanese barberry or other invasive shrubs like Asian bush honeysuckle displace native plants and wildlife dependent on those plants and also create tangles that make it difficult to walk through the forest.

In addition to herbs and shrubs, trees can also be in-vasive. Tree-of-heaven is an invasive Asian tree species that can grow 3 feet per year and reaches up to 60 feet tall, quickly overtopping and shading out our native trees in forest openings. Tree-of-heaven can also cause intes-tinal and heart problems in people exposed to its sap.

Most invasive plants depend on some kind of disturbance to get established in the for-est. Forest management ac-tivities, such as timber har-

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vesting, create opportunities for invasives to get established and spread. Invasive plants present in small numbers prior to forest management activity may ex-plode in growth following man-agement activity.

Since loggers and foresters rely on the long-term supply of forest resources, it is in their best inter-est to ensure the healthy regen-eration of forest stands to native tree species.

Learn to identify invasive plant species and watch for them. The sooner invasive plants are detected, the easier and cheaper it is to control them. Management costs escalate when invasive popula-tions are allowed to spread.

Initiate control of invasive species before harvest activities take place. Invasive plant populations quickly explode after distur-bance to the forest canopy and soils; decreasing their cover before harvest is a good way to avoid this dramatic increase.

Require the cleaning of timber harvesting equipment before it comes onto a new job site to prevent the movement of seeds of in-vasive species caught on tire treads and undercarriages.

What can you do to minimize the introduction and spread of invasive plants?

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Invasive plants can affect your ability to enjoy natural areas, parks, and campgrounds. Hik-ers, cyclists, and horseback riders all enjoy well-maintained trails, and invasive plants can grow over trails to the point that the path cannot be followed or can be difficult to navigate through. Dried and dying knapweed plants catch in bicycle chains, slowing the rider and stirring up dust as they are dragged.

Natural scenic beauty sought by recreationalists is degraded by in-vasive plants, which often form single-species stands, displacing attractive native flowers. The an-nual trek to see spring wildflow-ers or hunt for mushrooms may be disappointing when none can be found in a sea of garlic mustard.

Favorite camping spots taken over by spiny or dense shrubs can make it hard to find a good spot for a tent. Treating these infestations can eat up a natural area’s budget, leaving little funding for trail maintenance and other improvements.

Some invasive plants can have nasty effects on your health. Wild pars-nip or giant hogweed sap on skin exposed to sunlight can result in burns, blistering, and skin discoloration. The sap from leafy spurge

If I am a hiker, cyclist, or horseback rider . . . Why should I care?

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Native prairie plants

causes eye irritation. Spines on invasive thistles can become lodged in skin and cause irritation.

Many invasive plant seeds, such as those of burdock with its spiny seed balls, hitchhike on fur, increasing the effort needed to groom the horse or family dog after a hike. Some invasive plants, such as leafy spurge, are toxic to horses and mules.

Recreationalists can be vectors for in-vasive plant spread. Here are some things you can do to reduce the spread of invasive plants:

If I am a hiker, cyclist, or horseback rider . . . Why should I care?

Learn to recognize invasive plant infestations and avoid passing through them.

Report any infestations to the local land manager.

Check for seeds or plant parts and clean equipment, boots, an-imals, and gear between trips, or preferably when leaving an infested area.

Dispose of seeds in a plastic bag in a trash can.

Always use weed-free hay and feed for your animals.

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Boot brush station at entrance tonature preserve

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Leafy spurge

From the Great Lakes to the Mississippi River, the lakes and rivers of the Midwest provide stunning scenery and vital habitat for a wide variety of aquatic species. The spread of invasive plants threatens both the beauty of these areas and their ability to sustain fish and wildlife populations.

One common underwater invader is Eurasian watermilfoil, an aggressive plant that reduces native plant diversity and degrades fish habitat. Stud-ies have shown that Eurasian watermilfoil supports fewer aquatic inverte-brates, a vital source of food for fish, than native plants do. It also reduces oxygen levels in the water, leading to fish stress and fish kills, and clogs water intakes on motors causing engines to overheat.

One of the most widespread invasive plants in wetlands, lakeshores, and riverbanks is purple loosestrife, an extremely aggressive plant that replac-es diverse native plant communities with just a single species, greatly re-ducing the quality of wildlife habitat.

If I am a boater or angler, why should I care?

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Michigan Sea Grant: www.miseagrant.umich.edu

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Examples of the havoc that Eurasian watermilfoil can wreak on water recreation

Invasive plants can also increase the risk of flooding and soil erosion lead-ing to cloudy water, lower water quality, and silted spawning beds. Thick stands of invasive plants such as curlyleaf pondweed, Eurasian watermil-foil, and other submerged and floating aquatic plants can impede naviga-tion for anglers and boaters. In addition to invasive aquatic plants, boaters and anglers need to be aware of invasive aquatic animals such as zebra mussels, spiny waterfleas, round gobies, and Asian carp that also impact lakes and rivers of the Midwest.

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Remove visible plants, animals, and mud from your boat before leaving a waterbody.Drain all water from your boat, motor, bilge, live well, and bait contain-ers before leaving a water access.Clean and dry boats and equipment before entering another water-body.Dispose of unwanted bait in the trash, and never release plants and ani-mals into a waterbody unless they came from that waterbody.

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Boaters and anglers have the opportunity to help prevent the spread of aquatic invasive plants by following a few simple steps.

Zebra mussels

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Midwestern natural areas sup-port a great diversity of wildlife that hunters rely on and enjoy. However, invasive plants are in the process of degrading and even destroying many of these habitats.

For example, invasive plants such as Russian olive have taken over roadsides and natural areas in many parts of the Midwest, creating undesirable habitat for birds and mammals. Na-tive vegetation supports a much greater variety of birds than ar-eas infested with the invasive Russian olive.

Invasion of common reed in wetland ar-eas and along lake shores has a negative effect on water birds, including ducks and geese. Diverse native vegetation in wetlands and on lake shores generally results in higher waterfowl populations.

Invasive plants reduce the number and variety of forest wildlife, primarily by reducing the availability of food and suitable cover. For instance, invasive species like Asian bush honeysuckle can

If I am a hunter, why should I care?

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Russian olive

Common reed

shade out oak tree seed-lings and saplings and, over time, reduce the oak component of a forest. Fewer acorn-producing trees mean lower food availability and reduced habitat quality for wild-life such as white-tailed deer, squirrel, grouse, and turkey.

Invasive species can also turn an enjoyable stroll through the fields, woods, or wetlands while hunting into a painful trip through a tangled thorny mess in areas invaded with multiflora rose, an invasive plant with thorns that easily rip through clothes and skin. Other invasive plant species can also form dense tangles that are difficult to push through, even if they are not armed with thorns.

Invasive plants threaten our native ecosystems by altering the natu-ral communities that wild animals depend upon to produce food and cover. If invasive plants win, the native plants and wildlife lose, and so do the people who enjoy them.

Here’s what you can do to help:

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Clean your boots and gear after a hunting trip to make sure you aren’t carrying invasive plant seeds to new locations.

Don’t plant invasive plants for wildlife. Native species provide much better food and cover for native wildlife.

Learn to identify the invasive plants in your area and report any new sightings to local land managers.

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Hunter in a patch of multiflora rose

Invasive plant species not only threat-en our natural areas, they may invade your garden! Landscaping shrubs like Asian bush honeysuckle seed so freely into maintained landscapes that it is a continual challenge to rip them out be-fore they take over and displace other species you lovingly planted in your garden.

These aggressive species will also move from your land onto your neighbor’s land, decreasing both their enjoyment of their land and their enjoyment of having you as a neighbor.

Just because a plant is not spreading in your own garden, that doesn’t mean that the seeds from your plants aren’t spreading elsewhere. Purple loosestrife seeds, for instance, may wash from your yard into storm sewers and nearby waterways and germinate in moist areas like creek banks and lake shores.

Here are some things you can do to help.

If I am a gardener, why should I care?

Avoid using invasive species in your garden. Until you are able to get rid of invasive plants that may already be planted in your yard, be responsible and remember to remove and destroy seed heads of invasive plants. Also, don’t share invasives with other gardeners.

If you are worried that your garden will lose its luster after remov-ing invasives, it is easy to find non-invasive or native alternatives for invasive landscape plants. Before choosing a native plant alterna-tive, first think about the characteristics of the invasive plant you are replacing. For example, if you like the showy fruits of Asian bitter-sweet, try replacing it with American bittersweet. If you like Japanese honeysuckle for its vining habit, consider replacing it with a summer late-blooming vine like leatherflower vine. If you like purple loose-strife for its vibrant magenta flowers, try planting purple coneflower or one of the many native species of blazing stars instead.

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Invasive plants to watch for:Asian bush honeysuckles (Amur honeysuckle, Lonicera maackii; Morrow’s honeysuck-le, Lonicera morrowii; Tatar-ian honeysuckle, Lonicera ta-tarica; and Bell’s honeysuckle, Lonicera x bella)There are three species of bush honeysuckles and one hybrid from Asia that are aggressive

invaders in the Midwest. All four species are multi-stemmed shrubs reaching 2-6 meters in height. They have opposite, entire leaves, paired, showy flowers, and red or yellow fleshy berries. These species have been widely planted throughout the Midwest for landscaping and wildlife habitat and are highly invasive in forests. Bush honeysuckles prevent regeneration of forest trees and herbs and also provide poor habitat for nesting birds. Bush honeysuckles are difficult to control once they have reached high densities, so it is important to control new infestations as quickly as possible.

Buckthorns (common buckthorn, Rhamnus cathartica; glossy buck-thorn, Frangula alnus)Both species of buckthorn are deciduous shrubs that can reach up to 8 meters in height. They have elliptical leaves and produce abundant small, fleshy fruits that are black when ripe. Buckthorns were introduced to North America for use in hedgerows and for wildlife habitat. Glossy

buckthorn primarily invades wetlands and wet prairies but is also found in some forested areas. Common buckthorn is an invader of forested areas. Buckthorn fruits are consumed by a variety of birds and mam-mals, which aid in their disper-sal. These shrubs form dense thickets that prevent woody

seedling regeneration and may inhibit herbaceous understory growth in some areas. Common buckthorn has also been identified as an overwin-tering host for soybean aphids, a pest of soybean crops.

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Invasive plants to watch for:

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Garlic mustard (Alliaria petiolata)Garlic mustard, an invader of forests across the eastern U.S., is a bien-nial herb that was introduced from Europe in the 1860’s. During its

first year of growth, the plant forms a low-growing cluster of distinctive kidney-shaped leaves. It grows up to 40 inches tall in its second year, and can be recognized by its 4-pet-aled, white flowers and triangular stem leaves with toothed edges. Garlic mustard plants produce copi-

ous seeds, with as many as 3,000 seeds per plant. These seeds can sur-vive for up to 10 years in the soil, creating a lasting problem at invaded sites. Garlic mustard alters the chemistry of the soils where it grows by adding chemicals to the soil that prevent the growth of other plant species. In invaded areas, garlic mustard forms a single-species carpet on the forest floor.

Purple loosestrife (Lythrum salicaria)Purple loosestrife is easily recognized by its purple to magenta flowers composed of 5 to 6 petals, and its square stems. This species was intro-duced as an ornamental from Europe, where it is a minor component of wetland vegetation. Here in North America, purple loosestrife has escaped cultivation and is abundant in wetlands and other wet areas

(streambanks, lakeshores, and ditches) in almost every state in the U.S. Purple loosestrife forms dense single-species stands that cause a decline in plant diver-sity and affect wildlife by reducing food and habitat for waterfowl and spawning grounds for fish. A single plant can pro-duce 2.5 million seeds annually, and these seeds can be transported great distances by humans, animals, water, and wind. Fireweed is a common native plant that is often mistaken for purple loosestrife, but can be distinguished by having flowers with four petals and round stems.

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Asian bittersweet (Celastrus orbiculata) This woody vine was introduced from Asia for ornamental purposes. It is easily recognizable by its showy red fruits sur-rounded by papery yellow seed coats and is often used for wreaths and other deco-rations. Asian bittersweet closely resem-bles the native American bittersweet but can be distinguished by the position of its flowers and fruit; American bittersweet bears flowers and fruit only at the ends of vines, whereas the Asian species produces fruit all along the vine. Asian bittersweet grows quickly, and vines can reach up to 4 inches in diameter and nearly 60 feet in length. Trees and shrubs can be damaged or killed by the vine, which constricts sap flow, weakens limbs and trunks making them more susceptible to wind and ice damage, and shades out leaves growing underneath it. Asian bittersweet is also able to hybridize with American bittersweet, altering the genetic make-up of the species and further reducing rare native populations.

Multiflora rose (Rosa multiflora)Multiflora rose was intentionally introduced to North America as an ornamental because of its abundant, fragrant flowers, and has also been used for living fences and erosion control. This thorny shrub has be-come a menace in pastures, along roadsides, and in forested areas. It creates impenetrable thickets, reduc-ing growth of other plant species in natural areas. Multiflora rose is tolerant of a wide range of habitat con-ditions and grows aggressively once established. Multiflora rose can be distinguished from native roses by the presence of fringed stipules (small, green, leaf-like structures at the base of each leaf); stipules on native roses are not fringed.

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Common Reed (Phragmites australis)Common reed, often referred to by its Latin name as Phragmites, is a very tall grass, often reaching up to 3 or 4 meters in height. Grass blades are 1-5 cm in width and seed heads are large, showy, and feath-

ery in appearance. This plant spreads clonally and is an aggressive invader of wetlands. A stand of common reed can extend its boundaries by as much as 50 feet within one season. Common reed invasion can have major impacts on wetlands by reducing the quality of the habitat for invertebrates that fish and migratory waterfowl rely on for food. Although common reed is actually na-tive to the Midwest, the aggressive, in-vasive varieties are non-native in origin and can be distinguished from the native strains by a variety of characteristics, in-cluding darker leaves, much more rigid stems, and dense seedheads.

Japanese knotweed (Polygonum cuspidatum)Japanese knotweed is a large herbaceous perennial that forms dense thickets, especially in ri-parian areas, and can reach up to 10 feet in height. Distinguishing characteristics of this plant in-clude stems with swollen joints that are covered by a membranous sheath, sprays of small greenish-white flowers, and small, winged

fruits. Japanese knotweed is remarkably resilient, tolerating floods, drought, shade, high temperatures, and high salinity. Floods can fur-ther the spread of this species by carrying plant fragments downstream, which can root and sprout, forming new infestations.

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Canada thistle (Cirsium arvense)Canada thistle is an aggressive in-vader in prairies, savannas, and dunes, as well as a pest in pastures and agricultural fields. This spe-cies, which was introduced acci-dentally as a contaminant in crop seed, invades natural areas both by vegetative reproduction through rhizomes and by seed, which can be carried very long distances by wind and water. Canada thistle competes with other plants for water and nutrients, causing reductions in plant diversity and crop yields. It is avoided by cattle and eaten infrequently by deer. Before initiat-ing control efforts for Canada thistle, it is important to make sure you can recognize the differences between this species and native thistles, which are much less aggressive and are often rare.

Spotted knapweed (Centaurea biebersteinii)Spotted knapweed is a biennial or short-lived perennial with pink-ish-purple, thistle-like flowers and stem leaves that are covered with downy grayish hairs. It is be-lieved to have been introduced from Europe in the 1890’s as a contaminant in alfalfa or hay. Since its introduction to North America, this species has be-come one of the most problem-atic and widespread invasive plants in the western U.S. and is now spreading throughout the Midwest. Knapweed thrives in disturbed areas and spreads quickly once established. Cattle will not eat spotted knapweed because it has a bitter taste. Knapweed is espe-cially troublesome because of its ability to release toxic chemicals from its roots; these chemicals reduce growth and germination of neighbor-ing plants.

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Crown vetch (Coronilla varia)Crown vetch is a low-growing, herbaceous perennial vine with clusters

of small, pea-like white to purple flowers. It has been widely plant-ed along roads and waterways for erosion control but spreads easily into adjacent fields, prai-ries, and forest edges. This spe-cies has a rapid growth rate and is difficult to control, making it a great concern to landowners and land managers. Infestations of crown vetch reduce the abun-dance of native plants and the wildlife species that depend on

them. Crown vetch also alters soil chemistry by adding nitrogen to the soil, which has the potential to affect invaded areas even after the spe-cies is removed.

Eurasian watermilfoil (Myriophyllum spicatum)Eurasian watermilfoil was introduced to the United States in the 1940’s and has since spread to almost every state. This submersed aquatic

plant can be identified by its feather-like leaves ar-ranged in whorls of four around a long stem. Stems produce several branches which form a dense, float-ing mat on the water sur-face. Eurasian watermilfoil reproduces vegetatively; a single stem fragment can take root and form a new colony, growing on almost

any substrate. Dense mats of Eurasian watermilfoil reduce plant diver-sity and the quality of fish spawning habitat as well as interfering with swimming, boating, and other recreational activities.

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Cutleaf teasel (Dipsacus laciniatus)This species may have been introduced from Europe as early as the 1700’s, yet its abundance in the Midwest has increased rapidly in the past 20-30 years. Its range is believed to have expanded along high-way corridors, with seeds spread by mowing equipment. Cutleaf teasel is also commonly used in flower arrange-ments. When these arrangements are discarded or left behind in cemeteries, they can cause new infestations. Once established, cutleaf teasel can expand rapidly into prairies, excluding native vegetation. Teasel has a unique inflores-cence that makes it readily identifiable when flowers or seed heads are present.

Japanese stiltgrass (Microstegium vimineum)Japanese stiltgrass is an annual grass that thrives in forested areas with moist soils and along streambanks and ditches. It often makes its way into forests along trails or old logging roads and from there can rapidly spread into the forest understory, completely wiping out all other plants within just a few years. Stiltgrass has broad leaf blades that can be identified by the pres-ence of a pale, silvery stripe of hairs along the middle of the leaf on the upper leaf surface. Japanese stiltgrass is abundant in the southern part of the Midwest region and is rapidly moving northward.

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MYTH #3: All non-native species are bad.

FACT: Many non-native species do not cause problems in the areas where they are introduced and can be important for agriculture, hor-ticulture, medicine, or other uses. The species of concern are those that become invasive, taking over native ecosystems and crowding out native species. It is often dif-ficult to know in advance if a new species that is introduced will be-come invasive, so great caution should be used when importing or planting new species.

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Myths and Facts about Invasive Plants

MYTH #1: Invasive plants aren’t really a concern in the Midwest. They’re more of a problem in places like California and Florida.

FACT: While invasive plants may have received more attention and publicity in other parts of the country, invasive plants are just as big a problem here as they are in other regions. It is estimated that 18% of the plants in national parks in the Midwest are non-native species, many of which are highly invasive. The percentage of invasive plants is even higher in areas with greater disturbance from human activity, such as roadsides or pastures.

MYTH #2: Species move around and expand their ranges naturally. When people introduce a new species, it’s no different than the natural process of species movement.

FACT: People are moving far more species at a much faster rate than any natural colonization or range expansion. By bombarding our eco-systems with many new, aggressive species over a short time span, we are exposing them to conditions that would never occur without hu-man intervention.

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MYTH #4: I live in an urban area, so it doesn’t matter if I plant in-vasive species. They won’t be able to spread to natural areas from my yard.

FACT: Even if you don’t live near a natural area, your yard could be a source of invasive plants. Seeds of invasive plants can be carried in many ways—by birds eating fruits and depositing the seeds elsewhere, by water carrying seeds from your yard into sewers that lead to riv-ers or streams, or by car tires or shoe treads when you travel to parks, nature preserves, or recreational areas. The best way to prevent the spread of invasive plants is to not plant them in the first place.

MYTH #5: Cutting, hand-pulling, or mowing are the best ways to control invasive plants.

FACT: This is true in some instances. Small infestations of some spe-cies, such as garlic mustard, can be removed by hand-pulling. Howev-er, hand-pulling for large infestations leaves large patches of disturbed soil, and often seeds from the seed bank will germinate and re-colonize areas where garlic mustard has been removed. Properly-timed cutting or mowing can also control some species, however, perennials such as Canada thistle should not be cut or pulled. Removing only part of the plant will only stimulate growth and produce more plants. Combin-ing cutting with herbicides can be an effective method of treatment for many species.

Hand-pulling invasive plants Using herbicide to controlinvasive plants

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MYTH #6: Biological control methods such as insects are the an-swer to invasive plant problems.

FACT: There is no one miracle fix for controlling invasive plants. Relying on a single control method is unlikely to be successful. The best approach is an integrated management plan tailored to specific sites and species that includes a combination methods appropriate to the situation, such as chemical control (herbicides), biological control (insects or pathogens), mechanical control (pulling or cutting), and pre-scribed burning.

MYTH #7: Biological control is a bad idea, because it involves the release of non-native insects or pathogens that could damage native plants in addition to the targeted invasive plants.

FACT: In years past, some biological control efforts were poorly planned, and as a result, there were some unintended negative conse-quences of releasing non-native organisms to control invasive plants. These days, however, biological control agents are highly regulated and extensively tested prior to their release in the U.S. Scientists conduct careful experiments in quarantine facilities to determine whether po-tential biological control agents have the ability to feed or develop on plants native to the U.S. If the potential biological control agent does not feed on native plants and shows itself to be specific to the target invasive plant species, it can then be approved for release. Biological control agents should always be carefully monitored after their release to watch for any unanticipated effects on native ecosystems.

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Learn how to identify the invasive plants that are in your area.

Make sure that seeds are not stuck to your clothes or gear. You don’t want to introduce or spread these plants to other areas!

Do not camp or travel through areas infested with invasive plants, if they can be avoided.

Clean mud or dirt off your vehicle, pets, and even your hiking boots before going onto public lands.

Wash your boat before going to a new lake, river, or stream.

Drive on established roads and ride or hike on designated trails.

Don’t plant invasive species on your land. Find native or non-invasive alternative species to plant instead. Ask your local nursery to stock native plant species.

Volunteer to help inventory or control invasive plants. Early detec-tion and eradication of small infestations and prevention of new infestations are the most cost-effective ways to manage invasive plants. We need your help locating and eradicating the invasive plant species that have been described on the previous pages. Be on the lookout and help wipe out invasive plants.

Pass it on! Tell your friends and family about this problem.

Visit the Midwest Invasive Plant Network’s website for more informa-tion on invasive plants in our region.

How you can help . . .

mipn.org

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Illinois Illinois Department of Natural Resources, (217) 785-8688http://dnr.state.il.us/lands/education/ExoticSpecies/exoticspintro.htm

Chicago Wilderness (847) 242-6424, www.chicagowilderness.org/ IndianaIndiana Dept. of Natural Resources, Division of Entomology & Plant Pathology, Exotic & Invasive Pest Species Program, (317) 232-4120www.in.gov/dnr/invasivespecies/

IowaIowa Department of Natural Resources- Aquatic Nuisance Species Program Coordinator, (515) 432-2823www.iowadnr.com/fish/news/exotics/exotics.html- Invasive Species & Forest Health Coordinator, (512) 233-1161www.iowadnr.com/forestry/

MichiganMichigan Dept. of Agriculture, (517) 241-2977, www.michigan.gov/mda/

Michigan Invasive Plant Council, http://forestry.msu.edu/mipc/

MinnesotaMinnesota Dept. of Agriculture, www.mda.state.mn.us/pestsweeds.htm

Minnesota Department of Natural Resources, (651) 259-5131www.dnr.state.mn.us/invasives/index.html

MissouriMissouri Dept. of Conservation, (573) 751-4115, www.mdc.mo.gov/nathis/exotic/

Ohio Ohio Department of Natural Resources- Wildlife Mgmt. and Research Group, Division of Wildlife, 1-800-WILDLIFE- Division of Nature Preserves www.dnr.state.oh.us/dnap/invasive/

Ohio Invasive Plants Council, www.mipn.org/ohio

WisconsinPlant Conservation Program Manager, Bur. of Endangered Resources, WisconsinDept. of Natural Resources, (608) 267-5066, www.dnr.state.wi.us/invasives/

Invasive Plants Association of Wisconsin, www.ipaw.org

The mission of the Midwest Invasive Plant Network is to reduce the impact of invasive plants in the Midwest. To learn more about our work, please visit our website (www.mipn.org) or contact us at [email protected].

Additional Resources in Your Area

Missouri Invasive Plant Task Force (MoIP) 1

General Guidelines for Control 2

of Invasive Plants

Many citizens and groups are concerned with the control of invasive plants, for good reason,

and seek guidance on best control methods. There are certainly a variety of tools in the

invasive plant species management toolbox, including, but not limited to: prescribed fire,

hand pulling, digging, herbicide application (several application methods), grazing, mowing,

suffocation, and biocontrol agents. As with any job, we must ensure we are selecting the

appropriate tool, or combination of tools, to effectively and efficiently complete the task.

Each of the tools listed comes with a list of pros and cons that require careful consideration

before action is taken.[NM1]

MoIP has prepared this document to provide general guidelines on control methods. For

control of individual species, consult control fact sheets here. Methods of control in most

cases must be used in view of developing long-term management plans.

In addition to improving native habitats, invasive species control helps you understand the

soils and growing conditions of a particular location that you are working in and gives you a

more visceral connection to the landscape.

Considerations for Best Control Methods:

1. Ecological quality of your site. Protecting desirable plants—as well as insects/animals,

including those of conservation concern, and water quality—are important goals. From

1MoIP is a multi-agency, multi-industry networking and advocacy group to bolster statewide efforts to identify and control the invasive plant species that severely impact native biodiversity. 2 The intent of this document is to provide a broad overview of considerations for methods of control based on practitioner knowledge and ecological understanding.

http://moinvasives.org/resources/invasive-species-identification-and-management/

MoIP General Guidelines for Control of Invasive Plants

a conservation perspective, the usual outcome and ultimate goal of invasive plant

control is to benefit ecosystem health. Imprudent control methods can have the reverse

effect, however. For example, many herbicides, specifically those using a surfactant,

may harm aquatic animals if used near streams or other bodies of water. (However,

some herbicides without a surfactant may be less effective at actually killing the plant

for which they are intended.)

2. Specific species and plant life cycle. Some undesirable species (e.g., Johnson grass) may

grow amidst desirable plants (e.g., native, warm-season grasses) and efforts to control

the invasive species (e.g., with herbicide ) may accidentally kill desirable species.

Successful strategies to manage an invasive species and stop its spread result from:

a. Plant identification

b. Determination of why and how the invasive plant(s) has encroached in a specific

habitat

c. Understanding the life cycle (annual, biennial, perennial) and method of

reproduction of a species.

3. What is effective for the invasive species you are trying to control, and what is the

cost? In small areas, physical removal can be highly effective; however, if this results in

significant soil disturbance, it could cause soil erosion and may cause germination of

more invasive plants. In larger areas, herbicides, mowing, prescribed fire, or other

methods, or combination of methods, may be more cost-effective. Research on specific

species will be needed; user-friendly websites are available, and MoIP has compiled

numerous resources at moinvasives.org on specific species. If using herbicide, for

example, certain chemicals are effective on certain species and not on other species

(e.g., triclopyr kills broadleaf plants and brush, but not grass). Also, some chemicals have

short-term (days) effects, while other chemicals will have long-term (months) effects. In

addition, consider the cost of equipment, supplies, and labor for initial and future

treatment.

4. Timing and conditions. Management of an invasive may be better timed at one season

of the year or a particular stage of plant development. Some invasive plants have green

leaves in late fall and early spring when native plants are dormant, making the invasive

plants easy to spot and treat while eliminating risk to most native plants. One successful

approach is to target a species when the plants are small (< 6 inches), when infestations

are limited to small areas, or before plants are flowering and producing seeds. For

perennials, application of herbicides that move throughout the plant (systemic) is best

timed in the fall when plants re-charge their root system for the following year.

MOINVASIVES.ORG | 2

http://moinvasives.org/resources/


5. Human and environmental health. Consider the risks associated with methods of

control. If using herbicide, always be sure to use recommended personal protective

equipment (PPE) and follow label instructions. Federal standards state that minors

under the age of 16 should not use herbicides. Some herbicides are listed as Restricted

Use Pesticides and require a specific pesticide applicators license. MU Extension has a

publication, Pesticide Application Safety, which may be helpful to consult. Also keep in

mind the environmental risks of digging or pulling invasives, in terms of disturbance of

soil and desirable plants.

Read and follow all label instructions for all mechanized equipment and herbicides.

Whether buying ready-to-use or a concentrated form of herbicide, make sure you use

the correct percentage of active ingredient for the given treatment method.

SIDEBAR: If you are unable to manage invasive plants on your own, consider hiring a land

care professional or wildlife habitat/forestry contractor. The Grow Native! Resource Guide is

a good place to begin researching professional services for invasive plant control.

Common Control/Treatment Methods for Consideration

Pulling

Description: Use a tool or reach down and grab the plant with both hands (leather

gloves recommended) near the ground; pull, ensuring to get as much of the root as

possible. After removal from the soil, don’t let the plant be in contact with soil, or it may

re-root. This method varies depending on the plant species and soil conditions. Be

careful: skin contact with some plants can cause a rash (e.g., poison ivy). Make a brush

pile or hang the plant(s) on a log or tree to keep roots off the ground.

Pros: Removing adult plants reduces further seed production, has immediate visual

benefit, and can reduce shading. Also, avoids use of an herbicide.

Cons: Depending upon the density of plants pulled and amount of soil disturbed,

negative consequences can be disturbance of desirable plants, soil erosion, and

stimulating seeds of invasive plants. Labor intensive.

MOINVASIVES.ORG | 3

https://extension2.missouri.edu/g1916

http://grownative.org/resource-guide/


Timing/Conditions: Best when plants are fairly young/small. Ideal soil conditions allow

you to pull the roots easily. Some species pull harder than others; bush honeysuckle, for

example, pulls easily when the stem is pencil-sized in diameter. Be aware that there may

be more seeds in the soil seedbank, and new seedlings may germinate in disturbed soils

or with more light.

Effectiveness: If roots break off during pulling they may re-sprout; when you pull, pull

steadily and from different directions to avoid breakage. For large, perennial plants,

pulling is much less effective because of more established root systems.

Sites with excellent biological integrity: Avoid widespread disturbance of soil/roots.

Success is more probable for invasive plants in small areas or when plants are isolated

from desirable plants. Long-term monitoring and follow-up treatments are

recommended.

Root Docking for Shrubs and Trees

Description: Roots are severed right at the base of the plant to eliminate the root collar,

which is typically the site of resprouts. Effective tools include but are not limited to:

pruning knives, heavier sharpshooter shovels, mattocks, pulaskis, and reciprocating

saws.

Pros: No application of herbicide. There is limited resprouting as long as all remaining

roots are buried. There are no tripping hazards or brush to clean up in later seasons,

provided material is chipped, piled, burned, or otherwise removed. Follow up may be

minimal, however, new sprout growth that is common in areas newly exposed to

greater sunlight, and air movement may warrant monitoring.

Cons: Depending on the tool it may be physically demanding. It is not a fast method.

There is some soil disruption, but rarely enough to cause significant erosion.

Timing/Conditions: Root docking is a very flexible technique and can be performed year

round as long as plant identification is correct. Soil conditions affect the ease or

difficulty of the task. The amount of larger rocks in the soil may cause dulling of cutting

edges. It pays to stay diligent in managing and caring for tools. Be aware of other factors

such as grape vines in the canopy of the plant, dead logs on the ground that roots grow

under, proximity to overhead, dead limbs, and fallen trees in the canopy.

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Effectiveness: Very effective. Monitor in the following seasons as there may be new

seedling growth the following year from seeds in the seedbank, and management of

that growth does warrant monitoring in the following years.

Sites with excellent biological integrity: Few ‘high quality’ sites have larger/mature

invasive plants growing there, especially those known to have allelopathic qualities.

Root docking has the positive benefit of leaving a site ready for other restoration work.

Cut Stump

Description: Perennial plants that form permanent stems (shrub or tree) can be cut back

by various methods (chainsaw, weed-eater with brush blade, hand saw, loppers). Cut

every woody stem and apply application of appropriate herbicide immediately after

cutting. Regrowth from the root system will occur without application of an herbicide to

the cut surface within this time frame. For trees, the cambium tissue (rings of tissue just

inside the bark) is the living part of the plant and must be thoroughly covered to kill the

plant. Apply using a container and foam paint brush or a chemically resistant spray

bottle (consult recommended label percentages and species guide sheets). Use a

colored dye so that the applicator can easily distinguish treated from untreated plants.

Be sure not to treat the soil around the cut stump, because the adjacent plants’ roots

can absorb the herbicide. Properly dispose of excess solution. Be sure to follow

directions on the label and use personal protective equipment (PPE).

Pros: Very specific in targeting invasive plants growing among desirable plants. Can be

implemented May-January. If implemented February-April, an oil-based formula needs to be used, and the entire stump, including the bark, needs to be sprayed. Otherwise, active sap flow will flush the herbicide from the plant, and it will readily resprout.at Cons: Labor intensive,

but properly treated stumps should never re-sprout. Application of herbicide within 20

minutes of cutting the stem (depending on the herbicide used, for some herbicides this

time is much shorter; for others 20 minutes is adequate) is needed or the cut surface

will begin to heal over, making absorption of herbicide more difficult. Once cut, it can be

hard to find stumps. Therefore, it may be more effective to work in pairs; one person to

cut and another to apply herbicide. Over-application to the cut surface may cause

damage to surrounding plants through root absorption. Disposal of the above ground

portion may be desired, particularly if the plant is bearing fruits.

Timing/Conditions: Can be implemented any time during the year, but most effective

outside of spring; movement of sap downward in fall-winter will deliver more herbicide

MOINVASIVES.ORG | 5


to roots. Spring application is the least effective. Avoid herbicide application during

rainfall or under threat of rain.

Effectiveness: Good to excellent depending upon product. Complete coverage of cut

surface is necessary.

Sites with excellent biological integrity: Good choice, ensuring minimal collateral

damage to non-target species. (The only liability to this practice is the potential for

residue impacts of the herbicide on soil.)

Sidebar: A critical part of any invasive plant removal is choosing the most ideal method of

disposing of the plants. Whether you leave them in place to rot, potentially compromising the

use of the site for several years, or hanging the plants root up in the woods, again

compromising the visual quality of the site, chipping the material (if a chipper is available and

accessible to the site) or dragging them offsite, very labor intensive. This choice will always

depend on the location of the site and the capacity to deal with the brush.

Selective Herbicide Application to Foliage

Description: Walk with a backpack or handheld sprayer or use an ATV-mounted tank

with a hand wand, or a wick, properly identify the invasive plant, and spray herbicide to

thoroughly cover foliage. To avoid damage to desirable plants, target only invasive

species. Avoid spraying under windy conditions and be sure to not over-apply the

herbicide, which can cause dripping onto non-target species and the ground. Do not

spray at or above eye level.

Pros: Generally a practical application for larger areas; labor/treatment ratio is more

favorable than pulling/docking.

Cons: Off-target movement from spray or dripping from treated surfaces can lead to

injury of non-target plants. Cost of herbicide is a factor on large areas. Coverage of

foliage is challenging with dense stands of target plants.

Timing/Conditions: Applications more effective when plants fully leaf out and are

actively growing (late spring to early fall). Avoid windy conditions (>10 mph) or under

threat of rain.

Effectiveness: Good to excellent depending on product and size of target plants.

Sites with excellent biological integrity: It is necessary to evaluate sites (effective

identification crucial) to determine risk to non-target plants. Many invasive species have

MOINVASIVES.ORG | 6


extended growing seasons; application when desirable plants are dormant with actively

growing invasive plants can minimize injury to non-target species.

Non-selective Herbicide Application to Foliage

Description: Application of herbicide can occur through use of a vehicle-mounted

sprayer or by walking with a backpack, handheld sprayer or mist blower, spraying all of

the plants in an area. Selective damage to targeted plants can occur if only foliage of

target plants is visible or by use of a selective herbicide (e.g., control of invasive grasses

but no damage to broadleaf desirable plants). In extreme cases, aircraft application can

be utilized.

Pros: Large areas can be treated quickly when motorized equipment is used. Lower

labor costs.

Cons: Damage to non-target plants is likely. Cost of equipment and herbicides can be

high. Non-selective herbicides can kill all vegetation and lead to erosion.

Timing/Conditions: Applications more effective when plants fully leaf out (late spring to

early fall). Avoid windy conditions (>10 mph) or under threat of rain. Avoid applications

where chemicals can reach bodies of water.

Effectiveness: Good to excellent depending on herbicide selected.

Sites with fair to excellent biological integrity: Generally not recommended; likely to

cause loss of desirable plants; seek advice first.

Sidebar: Important points to consider: For a given invasive plant problem, consider resources

at your disposal and how best to use them: time, labor, funds. Consider also land

management/succession of other plants in a given area after invasives are removed. You may

want to integrate several methods for an effective management plan depending upon quality

of the site, season of the year and size of invasive plants. Often target plants can be present

at different sizes, with the control method selected for optimum control of each size.

Eradication of an invasive species will likely require multiple applications and semi-annual

inspection of treated areas. Avoid damage to non-target plants as that can open the canopy

and allow reinfestation of other invasive species.

Additional Methods for Consideration:

Prescribed Burning: Applying fire to the landscape in a controlled manner provides an

ecological treatment that can be effective in controlling some species of invasive plants if

MOINVASIVES.ORG | 7


burned every 2 or 3 years. However, burning should only be attempted by trained personnel. It

may be possible to obtain the necessary training, experience and equipment or to hire a

company providing this service.

Mowing, brush-hogging, or “bull-hogging”: Some species of invasive species are easily

controlled by mowing (and in some cases, mowing only once or twice a year is sufficient).

However, it may be undesirable to mow for a variety of reasons. Timing is critical; mowing

before plants have seeds can prevent seed formation on undesirable plants. Mowing after seed

set is detrimental as it helps disperse seeds. Bull hogging (named for the brand name “bull

hog,” a brand name of a mulching attachment) is for shrub and small tree species. Tree-shear

machines can have spray capacity, but bull hogs do not. Because shearers and bull hogs shred,

there is not much of a stump left to spray; the most effective method is to follow up the next

spring and foliar spray sprouts and new seedlings.

Prescribed Grazing: The use of prescribed grazing to set back heavy infestations of invasive

plant species can be a useful tool. Like mowing, it can be effective to defoliate invasive plants

and prevent seed formation; however, grazing animals may eat desirable plants as well. Properly timed,

high intensity grazing can have a significant impact on invasive populations. Three well-timed

goat-grazing defoliations with two years can kill up to 85% of bush honeysuckle or multiflora rose.

Follow up treatment will always be necessary to kill the remaining plants, and anything the goats can't

reach. Grazing should be coupled with a subsequent follow-up treatment, such as herbicide

application, to effectively kill invasives.

Digging: If you are not concerned about harming other plants, soil erosion, or encouraging

weed seed banks in soils, this may be something to consider for deep soils and relatively flat

terrains.

Shading and/or Suffocation: Tarping or applying mulch to an affected area may effectively

suffocate invasives over a period of time. Generally for small areas.

Plowing: In extreme cases on previously plowed land, this may be an effective method. Consult

with a professional.

Biological Controls: Biological control--controlling non-native, invasive species by introducing

their natural enemies--can be used as a management tool. The goal of biological control is to

reduce the population and corresponding impact of an invasive species to an acceptable level

so native flora and fauna can compete and persist.

The introduction of a non-native species to act as a biological control for an invasive species

requires rigorous scientific screening to ensure the biological control agent targets and impacts

only the invasive species and does not harm native species or impact human health. As such,

MOINVASIVES.ORG | 8


the use of biological controls should only be employed under the guidance of properly trained

professionals.

Using Nature’s Own Strengths: Foster a healthy ecosystem: Enables native plants to compete to the best of their ability.

Consider and prepare for what plants may, on their own, establish after removal of invasives.

Reduce disturbance: Avoid damage to non-target plants as that can open the canopy and allow

reinfestation of other invasive species. Whenever existing plants are killed and soil is exposed,

some species of plants that are adapted to disturbed soil become abundant in the first year or

two after the disturbance, but are naturally displaced by other plants as time goes on. These

“pioneer” species are less of a concern than other invasive species, however disturbed sites

provide favorable conditions for invasive plants. Therefore, if the site is fairly healthy to start

with, avoiding disturbance of the soil is a simple way to protect the site from invasion.

Choose which plant to favor: In some situations, it may be wise to permit a plant to grow, even

if it is undesirable, because it can act as the “lesser of two evils,” having a controlling influence

on another species that is more of a problem. For example, eastern red cedar thickets suppress

sericea lespedeza.

Example of a Decision-making Guide:

Bush Honeysuckle (bh):

Note: It is always important to take advantage of each plant’s innate weaknesses. In the case of

bh, its most prevalent weaknesses are its shallow root system and the proclivity of the seeds to

only last 1-2 years in the seedbank. It’s strengths are its ability to produce thousands of viable

seeds from one plant and its allelopathic tendency that leads it towards creation of a

monoculture if not removed. A full monoculture can potentially destroy a woodland, preventing

the establishment of the next succession of overstory trees to thrive, leaving a bh jungle in its

place.

1. If above head-high, cut stems near ground level and apply 25% glyphosate to cut stumps (cut

stump) or do Root Docking if the preference is not to use herbicide. a. If lower than head high, then evaluate other plants surrounding the target bh.

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b. If surrounding plants are high quality and bh is not thick, then pull bh or if pulling is likely to

break roots, then use cut stump treatment.

2. If surrounding plants are high quality and bh is thick and you have the ability to return when

natives are dormant, then mark the location on a map and plan to return later for selective

application to foliage.

a. If surrounding plants are not high quality, then apply selectively to foliage with 3%

glyphosate.

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city council agenda submission december 11, 2018

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