Common Invasive Plants of Concern along Streams in Monroe County, PA
Common Name
 Scientific name
 Control Methods*
 link
to more info
 Alternatives to plant*
 Vegetation** : click for larger picture
Flower**: click for larger picture







Garlic Mustard
 Alliaria petiolata
 hand removal to roots, cutting 2nd year plants before flowering, herbicides
 GM
 wild ginger, lady fern, evergreen wood fern, foam flower, creeping phlox, New York fern
 Garlic mustard, 1st year rosette
 spring flowers of garlic mustard
Japanese Barberry Berberis thunbergii
 small plants pulled by hand (use gloves).  Larger bushes should be clipped to base, then base and roots removed with pickax when soil is moist.  Herbicides glyphosate and triclopyr also effective.
 JB
 sweet pepperbush, spicebush, northern bayberry, pasture rose, highbush blueberry, swamp rose
 Japanese barberry bush in fall color
 close-up of barberry leaf
Japanese Stiltgrass
 Microstegium vimineum
 identification important to avoid removing natives.  Pull (including roots) for small infestations, herbicides for extensive infestations.
 JS
 plant native grasses
 Japanese stiltgrass. Note silver "stripe" down center of leaf
Japanese Knotweed
 Polygonum cuspidatum
 difficult!!! Small infestations pulled by hand, including roots & runners.  Herbicides: Glyphosate and triclopyr to cut stems or foliage.
 JK
 sweet pepperbush, Virginia sweetspire, maleberry, silky dogwood, fragrant or shining sumac
 Patch of Japanese knotweed along Crescent Lake Road
 Flowering branch of Japanese Knotweed
Multiflora Rose
 Rosa multiflora
 Young plants pulled by hand.  Mature plants controlled through frequent, repeated cutting.  Contact and systemic herbicides also effective.  Biological controls: rose-rosette disease spread by mites and wasps.
 MR
 common blackberry, flowering raspberry, pasture rose, swamp rose
 Multiflora rose growing along Cherry Creek, Monroe County, PA
 Flowering branch of multiflora rose
Common reed
 Phragmites australis
 Dig up entire plant, including root system or it will re-sprout.
 CR
 native wetland plants (sedges, grasses and rushes)
 Phragmites australis along Sullivan Trail, Monroe County, PA
 Phragmites growing along Brodhead River, Monroe Co., PA
Purple Loosestrife
 Lythrum salicaria
 Small infestations may be hand pulled, before seed set.  For extensive infestations in wetlands us Rodeo.  Biological control  by beetles most effective for long-term control
 PL
 Joe Pye weed, cardinal flower, New York ironweed, blazing star or gayfeather, obedient plant, blue vervain
 Purple loosestrife growing along Brodhead Creek, Monroe Co., PA
 Purple loosestrife flower
Spotted Knapweed
 Centaurea
maculosa
(syn. C. biebersteinii)
 hand pulled for small infestations (crown & taproot).  Herbicides for larger infestations, but may need to be repeated.  Be careful to clean tools and shoes to avoid spreading.
 SK
 plant native vegetation appropriate to site and conditions
 Whole young knapweed with tap root







* = Information from Swearingen, J., K. Reshetiloff, B. Slattery, and S. Zwicker. 202.  Plant Invaders of Mid-Atlantic Natural Areas.  National Park Service and U.S. Fish and Wildlife Service, Washington, D.C. 82 pp.
** = Pictures taken by Jerilyn Jewett-Smith, with an Olympus Stylus 300 digital  camera.

Other informational links for invasive identification, eradication and alternative plantings.  (Caution: these are pdf files and may take some time to download.)
USDA Invasive Plants Field and Reference Guide

Citizen's Guide to the Control of Invasive Plants in Wetland and
Riparian Areas

PA Guide to Invasive Riparian Plants

Last updated: 15 September, 2005: JJS