Honeysuckle- tartarian honeysuckle, Morrow’s honeysuckle, amur honeysuckle (Lonicera maackii, Lonicera tatarica)

• Multi-stemmed shrubs that grow 6-12 ft. tall

• Invades forest edges, woods, bogs, roadsides, pastures

• Alters habitats by decreasing light availability, outcompeting native species, depleting soil moisture and nutrients

• A native species to Asia and Russia, was introduced to North America as an ornamental shrub

• Removal and treatment of honeysuckle in the PCA: annually September- December

• Control: cutting shrubs at the base of trunks and immediate application of glyphosate herbicide to stumps. Stumps readily re-sprout; yearly follow-up treatment is necessary to eradicate completely
  
  (Photo by Janeson Keeley on Unsplash)

Dame's Rocket (Hesperis Matronalis)

• Perennial or biennial that grows 3-4 ft. tall. White, pink or purple flowers emerge in the spring. Often mistaken for the native wood phlox (however, dame’s rocket flowers have 4 petals, wood phlox has 5 and each bloom in different seasons)

• Invades woodlands, roadsides and open areas

• Crowds out and displaces native plant species 

• A native species to Eurasia, introduced to North America as an ornamental species. Often found in “wildflower” seed mixes and gardeners should use caution when choosing “wildflower seed mixes” to ensure dame’s rocket is not included

• Removal of dame’s rocket in the PCA begins in early spring and continues throughout the summer until plants set seed

• Control: hand pulling plants by the roots, bagging and disposing of off-site

Wild Parsnip (Pastinaca sativa)

• Biennial/perennial herb that grows up to 4 ft. tall. Produces hundreds of small yellow flowers arranged in a loose umbel that bloom in the summer. Skin contact with the plant sap causes intense burning and blistering on sunny days, a condition called phytophotodermatitis 

• Invades fields, meadows, disturbed sites

• Can form dense monoculture stands that replace native habitat

• A native to Eurasia, brought to North America as a cultivated root vegetable 

• Control of wild parsnip begins in spring and continues throughout summer. Proper skin protection is necessary when working on control of this plant!

• Control: digging out taproots or repeated mowing/trimming of flower heads to prevent seed spreading

Garlic Mustard (Alliaria petiolata)

• Herbaceous biennial that grows 2-4 ft. tall. First year plant grows as a green rosette, second year plants produce several flowering stems with white flowers

• Invades floodplain forests, savannas, roadsides

• Alters habitat by exuding antifungal chemicals into the soil that disrupts native plant growth, also outcompetes native plants for space, sunlight, nutrients

• A native species to Europe, was introduced into North America as a desirable herbal, edible and medicinal plant and for erosion control

• Removal of garlic mustard in the PCA begins early spring and continues throughout the summer until plants set seed

• Control: hand pulling plants by the roots, bagging and disposing off-site

Common Burdock (Arctium minus)

• Taproot biennial forb that grows about 3-6 ft. tall. Purple flowers bloom in summer, and dry to a velcro-like burr. Produces large, heart-shaped leaves

• Invades disturbed and degraded meadows, grasslands, woodland and riparian habitats

• Negatively affects native plants by being a host for pathogens like powdery mildew and root rot. Large leaves can shade out nearby plants. Also poses a risk to birds and bats that can be trapped in burr clusters

• A native species to Europe, was introduced to North America for medicinal purposes

• Removal of burdock in the PCA begins in spring and continues throughout the summer

• Control: hand pulling small plants and digging out large taproots 
  
  (Photo by Truly Joy on Unsplash)
  
   

Reed Canary Grass (Phalaris arundinacea)

• Perennial cool season grass that grows about 2-6 ft. tall. Reproduces through horizontal stems below the soil surface (rhizomes)

• Invades wetlands, moist fields and roadsides

• Outcompetes most native species in wetlands. Dense infestations reduce plant and insect biodiversity

• A native species to Eurasia, it was introduced to North America for forage and erosion control 

• A particularly aggressive invader, the PCA has not yet begun mitigation and removal of reed canary grass

• Control: a combination of mechanical and chemical control methods has proven most effective: repeated mowing and appropriately timed herbicide for at least 3-5 years

Learn more on this UW-GB site.

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(Photo by Gary Fewless)