				Massachusetts Invasive Plants

Invasive Plant Species of Massachusetts

MassWildlife
A Guide to Invasive Plants in Massachusetts

by: Pamela B. Weatherbee, Paul Somers and Tim Simmons
The Massachusetts Biodiversity Initiative

Why Are Some Non-Native Plants a Serious Threat?

Plants introduced from somewhere else leave behind the diseases and herbivores that kept them under control in their native habitats. This provides them with an advantage that allows them to crowd out native species.

Some non-native plants were introduced deliberately for their vigorous, growth potential: exceptional for erosion control, but a big problem for slower growing native plants. A few were selectively bred to produce abundant fruits and seeds attractive to birds and other wildlife - and thus are readily spread by these animals into many habitats. Others arrived unintentionally in a variety of ways and their spread has been accelerated by human activities and pathways of transportation. Most of these plants thrive in disturbed areas: roadsides, abandoned fields, right-of-way corridors and ditches.

These invasives, typically called non-native species (also called "exotics" or "alienweeds") often occur in huge patches - one species taking the place of a great variety of native plants - thus reducing the biodiversity of natural areas.

Why do we need biodiversity? Our plants and animals have evolved together for thousands of years, developing into a closely interwoven web of life, with many animals and plants dependent on specific species for their survival. Invasive plant populations change the characteristics of these complex webs and can lead to the elimination of many plants and animals. For example, some butterflies require a specific food plant, and many plants require specific pollinators. If invasive plants crowd out the species the butterfly needs, or the ones the special pollinators need, whole sections of the web can collapse, diminishing the wildlife community. Do we really want a world of just starlings and dandelion?

Plants have been moving around the landscape and evolving since life began. However, these current invasions of aggressively spreading plants are not natural range extensions (which would include natural control agents and give native species time to develop competitive strategies). They are moving so fast and are so overwhelming that many native species simply cannot contend with them. All too frequently, natural habitats are degraded by multiple invasive species.

Many of these "bad plants" are still being planted because they seem to fill a particular need for fast growing erosion control, visual screening, windbreaks, wildlife food, or even as garden plants. Native plants can and should be used to fill those needs. Some are available in nurseries and seed catalogs, and others are being studied for their potential uses.

Most introduced species, such as garden, meadow, and agricultural species, are NOT harmful. Only a few are troublemakers. If we know the characteristics of a plant we may be able to predict how it will behave; whether it will spread like wildfire or stay where it is planted. Responsible introduction of new species or varieties should involve careful research and testing before release.

A Typical Harmful Invasive Plant

Grows and matures rapidly;
Spreads quickly;
Can flower and/or set seed all season;
Has no known diseases or pests to control it;
Thrives in many habitats;
Is difficult to remove or control.

What Can We as Individuals and Organizations Do?

First, be aware of the value of our native habitats to wildlife and the dangers posed by invasive non-natives.

Join local groups that are introducing people to the enjoyment of local native habitats and wildlife communities.

Don't plant invasives or spread them inadvertently (for instance, collecting oriental bittersweet for fall or winter decorations, and later discarding the stems, fruit and seed outside).

Learn to identify the most invasive species. The ones featured on the following pages are among the worst currently found in Massachusetts.

If you notice new or small populations of invasive species on public land or nature reserves, notify the managers. Caught in time, the weeds may be controlled; otherwise it will involve expensive arduous labor to remove them. Land managers are in a good position to take action against new invaders.

If you are a landowner or land-manager, be vigilant for the appearance of invasive species on your property. Learn how to eradicate or control them (this booklet should help), and take steps to do so before they become a serious problem.

Don't disturb soil or vegetation in natural areas unnecessarily. Undisturbed natural areas are resistant to invasion.

Encourage the planting of native species in municipal and town gardens, memorial sites, parks, traffic islands, etc. Ask your nursery to stock more native species; point out any plants for sale at your nursery that are known to be harmful invasives.

Contact the Division of Fisheries and Wildlife, the Wildflower Society, your local garden club and other environmental organizations for information on what to plant. Join conservation organizations that are protecting natural habitats, plants and wildlife.

Control of Invasive Plant Species

An exotic plant invasion can move through an area with the speed of an epidemic. Like a disease, eliminating it right away, or better yet, preventing its introduction in the first place, is always the best medicine. Pulling or killing a few stems, saplings or seedlings when they first appear may prevent an insurmountable problem later. (Make sure you've correctly identify the plant first; don't destroy native species by mistake!)

Attacking the problem by hand with the aid of a few gardening tools is least destructive to the habitat; plants can be pulled, mowed or cut. Always keep in mind that each species will respond differently to each control method. Some sprout prolifically when cut, for instance, and may require multiple cuttings for several years before their roots will finally die. Find out what works for the species you are dealing with, and what methods may make matter worse.

Treating invasive plants with herbicides is often an effective control method, but it should be used cautiously and with discretion. Other alternatives should always be considered first. Be sure to read and follow instructions on herbicides sold over the counter at stores and garden centers. Consider seeking professional advice from licensed applicators or the state Pesticides Bureau in the Massachusetts Department of Food & Agriculture. When considering application in or near wetland areas, town conservation commissions or administrators must be consulted.

Invasive Plant Species Occuring in Massachusetts

The following is a list of non-native plants recorded in Massachusetts which possess strongly invasive characteristics. Those which are currently presenting the greatest threat to native plant communities are highlighted. Remember, however, that some species which are not highlighted may eventually become major problems, and that others may not become widespread problems.

COMMON NAME	SCIENTIFIC NAME
Amur honeysuckle	*Lonicera maackii*
Autumn olive	*Elaeagnus umbellata*
Barnyard grass	Echinochloa crusgalli
Black locust	*Robinia pseudoacacia*
Black swallow-wort	*Cynanchum louiseae*
Bittersweet nightshade	Solanum dulcamara
Bushy Rock-cress	Cardamine impatiens
Canada bluegrass	Poa compressa
Chervil	Anthriscus sylvestris
Coltsfoot	Tussilago farfara
Common barberry	*Berberis vulgaris*
Common buckthorn	*Rhamnus cathartica*
Common / hedge privet	Ligustrum vulgare
Common mullein	Verbascum thapsus
Creeping buttercup	Ranunculus repens
Curly pondweed	Potamogeton crispus
Cypress spurge	Euphorbia cyparissias
Dame's rocket	Hesperis matronalis
Eurasian water-milfoil	Myriophyllum spicatum
Fanwort	Cabomba caroliniana
Garlic mustard	Alliaria petiolata
Giant waterweed	Egeria densa
Glossy buckthorn	Rhamnus frangula
Goutweed or Bishop's weed	Aegopodium podagria
Hair fescue	Festuca filiformis
Hairy willow-herb	Epilobium hirsutum
Japanese barberry	Berberis thunbergii
Japanese honeysuckle	Lonicera japonica
Japanese hops	Humulus japonicus
Japanese knotweed	Polygonum cuspidatum
Japanese privet	Ligustrum obtusifolium
Japanese rose	Rosa rugosa
Kiwi vine	Actinidia arguta
Kudzu	Pueraria montana
Lesser naiad	Najas minor
Live-forever or Orpine	Sedum telephium
Money wort	Lysimachia nummularia
Morrow's honeysuckle	Lonicera morrowii
Morrow's X Tatarian honeysuckle (hybrid)	Lonicera xbella
Multiflora rose	Rosa mutiflora
Norway maple	Acer platanoides
Oriental bittersweet	Celastrus orbiculata
Phragmites, Reed grass	Phragmites australis
Porcelain berry	Ampelopsis brevipedunculata
Purple loosestrife	Lythrum salicaria
Reed canary-grass	Phalaris arundinacea
Russian olive	Elaeagnus angustifolia
Sea- or horned poppy	Glaucium flavum
Sheep fescue	Festuca ovina
Sheep-sorrel	Rumex acetosella
Silver lace-vine	Polygonum aubertii
Silver poplar	Populus alba
Spotted knapweed	Centaurea biebersteinii
Sweet reedgrass	Glyceria maxima
Sycamore maple	Acer pseudoplatanus
Tartarian honeysuckle	Lonicera tartarica
Tree-of-heaven	Ailanthus altissima
True forget-me-not	Myosotis scorpioides
Water-chestnut	Trapa natans
Watercress	Rorippa nasturtium-aquaticum
Wetsern catalpa	Catalpa speciosa
White mulberry	Morus alba
Wild thyme	Thymus pulegioides
Winged euonymus	Euonymus alata
Variable water-milfoil	Myriophyllum heterophyllum
Yellow floating heart	Nymphoides peltata
Yellow iris	Iris pseudacorus

GWLT Note: After reading through a listing like this people are often left with questions. For the best contact in Massachusetts on invasive plants, addressing them, and native alternatives to them please check out the extensive work offered by the New England WildFlower Society.

Greater Worcester Land Trust
(508)795-3838
101 Water Street, Worcester, MA 01604
E-mail: mail@gwlt.org
URL:http://www.gwlt.org

Suggestions, Questions, & Site Survey

Designed by: Colin M.J. Novick, Project Coordinator
August 9th, 2007

MassachusettsInvasive Plants