Plant Invaders of Mid-Atlantic Natural Areas Revised & Updated – with More Species and Expanded Control Guidance National Park Service U.S. Fish and Wildlife Service 1 I N C H E S 2 Plant Invaders of Mid-Atlantic Natural Areas, 4th ed. Authors Jil Swearingen National Park Service National Capital Region Center for Urban Ecology 4598 MacArthur Blvd., N.W. Washington, DC 20007 Britt Slattery, Kathryn Reshetiloff and Susan Zwicker U.S. Fish and Wildlife Service Chesapeake Bay Field Office 177 Admiral Cochrane Dr. Annapolis, MD 21401 Citation Swearingen, J., B. Slattery, K. Reshetiloff, and S. Zwicker. 2010. Plant Invaders of Mid-Atlantic Natural Areas, 4th ed. National Park Service and U.S. Fish and Wildlife Service. Washington, DC. 168pp. 1st edition, 2002 2nd edition, 2004 3rd edition, 2006 4th edition, 2010 1 Acknowledgements Graphic Design and Layout Olivia Kwong, Plant Conservation Alliance & Center for Plant Conservation, Washington, DC Laurie Hewitt, U.S. Fish & Wildlife Service, Chesapeake Bay Field Office, Annapolis, MD Acknowledgements Funding provided by the National Fish and Wildlife Foundation with matching contributions by: Chesapeake Bay Foundation Chesapeake Bay Trust City of Bowie, Maryland Maryland Department of Natural Resources Mid-Atlantic Invasive Plant Council National Capital Area Garden Clubs Plant Conservation Alliance The Nature Conservancy, Maryland–DC Chapter Worcester County, Maryland, Department of Comprehensive Planning Additional Fact Sheet Contributors Laurie Anne Albrecht (jetbead) Peter Bergstrom (European watermilfoil) Kathy Bilton (nodding star-of-Bethlehem) Meghan Fellows (yellow archangel) Richard Hammerschlag & Brent Steury (marsh dewflower) Kerrie Kyde (wavyleaf basketgrass) Roy Miller (hydrilla) Michael Naylor (water chestnut) Kathryn Reshetiloff (Japanese honeysuckle, white mulberry, sawtooth oak, common periwinkle) Rod Simmons (broadleaf helleborine) Julie Slacum (privets) Edith Thompson (butterflybush, Japanese silver grass, daylily) Mary Travaglini (linden viburnum) Alan Whittemore (Callery pear) Reviewers Philip Pannill (control options), Selma Sawaya (general proof-read- ing), John Peter Thompson (various), Joe DiTomaso (ravenna-grass) Cover Image Common periwinkle (Vinca minor) by Bill Johnson 2 Preface Contrary to the title, the focus of Plant Invaders of Mid-Atlantic Natural Areas is native biodiversity. Invasive species and habitat destruction, intensified by global climate change, are running neck-to- neck as the leading causes of environmental despoliation and loss of biological diversity worldwide. The ever-expanding human population and associated demand on limited natural resources are driving this worldwide problem. International trade provides a means to satisfy the great demand for exotic things but has resulted in the introduction of plants, insects and pathogens that are harmful to our environment and human health. Preserving remaining intact natural habitats, reestablishing native plants, managing overabundant white- tailed deer populations and restoring natural hydrologic and other conditions are some steps we can take to mend degraded lands. This fourth edition has been updated, expanded and reorganized to provide more information in a more efficient manner. The book now includes information on 80 species (up from 60 previously) and expanded control guidance. A new section called “Plants to Watch” has been added which includes a number of species that may not be widespread but are increasingly catching the attention of ecologists, land managers and others as being invasive in natural habitats. Native plant alternatives have been consolidated in a separate section. For the purposes of this manual, the mid-Atlantic region includes the District of Columbia and the states of Delaware, Maryland, New Jersey, Pennsylvania, Virginia and West Virginia. About 280 exotic plant species have been identified by experts as being invasive in natural areas in this region. A complete list is available from the Invasive Plant Atlas of the United States (see References). As of this printing, the Invasive Plant Atlas shows 1,173 plants having been reported to be invasive in natural areas in the U.S. This guide should be used as an introduction to invasive plants and the impacts they are having on natural habitats and ecosystems. Plants not included here should not be assumed to be non-harmful. This book is dedicated to Gail Sharabi who inspired my first Weed Buster event at Brookside Gardens in Wheaton, Maryland on Columbus Day in 1993. 3 Table of Contents Preface ............................................................................................................... 3 Table of Contents ............................................................................................... 4 Introduction ....................................................................................................... 7 Aquatic Plants Eurasian Water-Milfoil (Myriophyllum spicatum) ............................... 14 Giant Salvinia (Salvinia molesta) ............................................................. 16 Hydrilla (Hydrilla verticillata) ................................................................ 17 Parrot-Feather (Myriophyllum aquaticum) .......................................... 19 Water Chestnut (Trapa natans) ............................................................... 21 Grasses and Sedges Bamboos (Bambusa vulgaris, Phyllostachys aurea and Pseudosasa japonica) ............................................................................. 23 Bog Bulrush (Schoenoplectus mucronatus) ........................................... 24 Common Reed (Phragmites australis) .................................................... 26 Japanese Stiltgrass (Microstegium vimineum) ..................................... 28 Wavyleaf Basketgrass (Oplismenus hirtellus ssp. undulatifolius) .... 29 Control Options ........................................................................................... 31 Herbaceous Forbs Beefsteak Plant (Perilla frustescens) ...................................................... 36 Canada Thistle (Cirsium arvense) ........................................................... 37 Chinese Lespedeza (Lespedeza cuneata) ................................................ 38 Common Daylily (Hemerocallis fulva) .................................................... 40 Dame’s Rocket (Hesperis matronalis) ..................................................... 41 European Stinging Nettle (Urtica dioica) .............................................. 43 Fig Buttercup (Ficaria verna) .................................................................. 44 Garlic Mustard (Alliaria petiolata) .......................................................... 45 Ground Ivy (Glechoma hederacea) ........................................................... 47 Japanese Knotweed (Fallopia japonica) ................................................ 48 Nodding Star of Bethlehem (Ornithogalum nutans) and Sleepydick (Ornithogalum umbellatum) ............................................ 50 Purple Loosestrife (Lythrum salicaria) .................................................. 51 Spotted Knapweed (Centaurea stoebe ssp. micranthos) ...................... 53 Control Options ........................................................................................... 55 Shrubs and Subshrubs Amur Honeysuckle (Lonicera maackii) .................................................. 61 Autumn Olive (Elaeagnus umbellata) .................................................... 62 Japanese Barberry (Berberis thunbergii) ............................................... 64 Japanese Meadowsweet (Spiraea japonica) ........................................... 65 Linden Viburnum (Viburnum dilatatum) ............................................... 66 Morrow’s Honeysuckle (Lonicera morrowii) .......................................... 68 Multiflora Rose (Rosa multiflora) ............................................................ 69 4 Privets (Ligustrum obtusifolium, L. ovalifolium, L. sinense and L. vulgare) ................................................................................................ 71 Wineberry (Rubus phoenicolasius) ......................................................... 72 Winged Burning Bush (Euonymus alatus) ............................................ 73 Control Options ........................................................................................... 75 Trees Callery Pear (Pyrus calleryana) .............................................................. 80 Norway Maple (Acer platanoides) ........................................................... 82 Paper Mulberry (Broussonetia papyrifera) ........................................... 83 Princess Tree (Paulownia tomentosa) .................................................... 84 Silk Tree (Albizia julibrissin) ................................................................... 86 Tree of Heaven (Ailanthus altissima) ..................................................... 87 White Mulberry (Morus alba) ................................................................... 89 Control Options ........................................................................................... 91 Vines Black Swallow-Wort (Cynanchum louiseae) .......................................... 99 Chinese Wisteria (Wisteria sinensis) ..................................................... 101 Chocolate Vine (Akebia quinata) ..........................................................