Their Identification and Control By: Natalie George, Field Botanist Common Weeds of Native Landscapes: Their Identification and Control Focus Types of Native Landscapes Raingardens Prairies and Meadows Categories of Weeds Class I, II, and III (Herbaceous only) Focus Species Canada Thistle, Crown Vetch, Tall Fescue, Purple Loosestife, Sweet Clover, Reed Canary Grass, Johnson Grass, Birdsfoot Trefoil, Curly Dock Rain Gardens Prairies and Meadows Weeds Can be divided into the following classes: Class I – High Priority (Invasive and Prohibited Noxious) Class II – Medium Priority (Restricted Noxious) Class III – Low Priority Class I – High Priority Herbaceous Canada Thistle – Cirsium arvense Crown Vetch – Coronilla varia Queen Anne’s Lace – Daucus carota Tall Fescue – Festuca arundinacea Purple Loosestrife – Lythrum salicaria Sweet Clover – Melilotus officinalis Reed Canary Grass – Phalaris arundinacea Canada Goldenrod – Solidago canadensis* Johnson Grass - Sorghum halapense Cattails – Typha sp.* *native Class II – Medium Priority Herbaceous Bull Thistle – Cirsium arvense Birdsfoot Trefoil – Lotus corniculatus Timothy – Phleum pretense Curly Dock – Rumex crispus Red Top – Tridens flavus Red Clover – Trifolium pratense Turfgrass varieties – Multiple species Class III – Low Priority Herbaceous Common Ragweed – Ambrosia artemisiifolia Giant Ragweed – Ambrosia trifida Horseweed – Erigeron canadensis Foxtail – Setaria sp. Brief Overview of Treatment Methods Foliar application Water based herbicide solution Applied with backpack or tank sprayers Can be used very selectively BBT (Basal bark treatment) Oil based herbicide Applied with backpack sprayer with very low pressure Primarily used for woody species Cut stump Water based herbicide solution Applied with backpack with sponge or hand sprayers Very specific application Focus Species Canada Thistle – Cirsium arvense Crown Vetch – Coronilla varia Tall Fescue – Festuca arundinacea Purple Loosestrife – Lythrum salicaria Sweet Clover – Melilotus officinalis Reed Canary Grass – Phalaris arundinacea Johnson Grass - Sorghum halapense Birdsfoot Trefoil – Lotus corniculatus Curly Dock – Rumex crispus Canada Thistle – Cirsium arvense Asteraceae Rhizomatous perennial Native to Mediterranean and Europe Prohibited noxious weed Distinguished from native thistles by leaf underside Canada Thistle – Cirsium arvense Canada Thistle Control Foliar application – 1% Clopyralid+surfactant+dye (Legume and Composite family specific) Prevent seed production Hand pulling - almost impossible due to extensive underground root system Crown Vetch – Coronilla varia Fabaceae Perennial, sprawling groundcover Native to Europe, southwest Asia, Africa Invasive No specific native look-alikes, but be aware of: Bundle flower Crown Vetch – Coronilla varia Crown Vetch Control Foliar application – 1% Clopyralid+surfactant+dye (Legume and Composite family specific) Foliar application – 1% Triclopyr 3 + 0.5% Clopyralid+surfactant+dye (Effective on many tough broadleaf plants) Foliar application – 3% Triclopyr 3+surfactant+dye (Water Safe Option) Tall Fescue – Festuca arundinacea Poaceae Clump forming, rhizomatous perennial Native to Europe Invasive No specific native look-alikes Tall Fescue – Festuca arundinacea Tall Fescue Control Foliar - 2% Glyphosate+surfactant+dye (use water safe formulation if necessary) Foliar application – 1% Clethodim+surfactant+dye (grass family specific, not water safe) Hand pulling – ideal for small situations when clumps are just becoming established. Be sure to remove all stem material where roots attach. Purple Loosestrife – Lythrum salicaria Lythraceae Rhizomatous perennial Native to Eurasia Invasive! Federally regulated Distinguish from native Winged Loosestrife. Purple Loosestrife – Lythrum salicaria Purple Loosestrife Control Foliar – 2-3% glyphosate+surfactant+dye (Repeat treatment highly likely due to seed bank) Hand pulling – possible for very small infestations Sweet Clover – Melilotus officinalis Fabaceae Biennial with semi-woody taproot and extensive secondary fibrous roots Native to Eurasia Invasive No specific native look-alikes, but be aware of: White and Purple Prairie Clover Roundheaded Bushclover Sweet Clover – Melilotus officinalis Sweet Clover Control Foliar application – 1% Clopyralid+surfactant+dye (Legume and Composite family specific) Foliar application – 1% Triclopyr 3 + 0.5% Clopyralid+surfactant+dye (Effective on many tough broadleaf plants) Foliar application – 3% Triclopyr 3+surfactant+dye (Water Safe Option) Hand Pulling - This can be effective for small infestations and for control of seed production. Reed Canary Grass – Phalaris arundinacea Poaceae Perennial, extremely rhizomatous Native to Europe, Asia and North America Invasive Not practical to distinguish native genotype Distinguish from native Bluejoint Grass Reed Canary Grass – Phalaris arundinacea Reed Canary Grass Control Foliar – 3% glyphosate+surfactant+dye (use water safe formulation) Fire? – Repeated burns for subsequent years Johnson Grass - Sorghum halapense Poaceae Rhizomatous perennial, clumping, forms dense stands Native to Mediterranean region Prohibited Noxious Weed Distinguish from native silver plumegrass Johnson Grass - Sorghum halapense Johnson Grass Control Foliar application – 1% Clethodim+surfactant+dye (grass family specific, not water safe) Foliar application –3% Glyphosate+surfactant+dye (use water safe formulation if necessary) Prevent seed production, by hand cutting, removing flower heads. Can dig rhizomes, but very intensive. Cut-stump?? Birdsfoot Trefoil – Lotus corniculatus Fabaceae Perennial, prostrate and mat-forming Native to Eurasia and North Africa Introduced No specific native look-alikes, but be aware of: Bundle flower White and Purple Prairie Clover Roundheaded Bushclover Birdsfoot Trefoil – Lotus corniculatus Birdsfoot Trefoil Control Foliar application – 1% Clopyralid+surfactant+dye (Legume and Composite family specific) Can dig plants for small infestations, be sure to remove all roots Curly Dock – Rumex crispus Polygonaceae Taprooted perennial , forms basal rosettes Native to Eurasia Restricted noxious weed Distinguish from native docks- swamp, pale, Mexican Curly Dock – Rumex crispus Curly Dock Control Foliar application – 3% Triclopyr 3+surfactant+dye (Effective on many tough broadleaf plants) Foliar application – 3% Glyphosate+surfactant+dye (use water safe formulation when near water) Cut and bag seeds, dispose in landfill Hand pulling – difficult, but can be effective after a rain for small populations Cut-stump?? Disclaimer! Be sure to read and follow labels Lot of available information Information presented today: Known to work for situations WE work in May not be applicable to all sites Various climates (microhabitats) affected differently Photo Credits: Eco Logic staff Illinois Wildflowers www.illinoiswildflowers.info Gary Fewelles www.uwgb.edu Global Invasive Species Database Invasive.org Jeffrey Pippen [email protected] JK Marlow [email protected] K. Chayka www.minnesotawildflowers.info Oregon State University forages.oregonstate.edu Peter M. Dziuk www.minnesotawildflowers.info T. Butler stephenville.tamu.edu USDA Plants Database Questions? .