Ornamental Jewelweed, Impatiens glandulifera

• Herbaceous annual
• Large pink to purple flowers from midsummer to fall
• Attracts pollinators and draws them away from native plants

• Spreads by seed via water and sediment erosion, can also sprout roots from nodes along the stem
• Native to Pakistan, India and Nepal
• Introduced as an ornamental plant

Management techniques:

• Consistent and-pulling, weed-whacking, and mowing before flowering 

Properly dispose of all discarded plant material

White Sweet Clover, Melilotus albus

• Tall, biennial herb
• Small, white "pea" flowers
• Long taproot that can produced multiple aboveground stems

• Spread by seed via animal dispersal. Seeds stay viable for 14+ years
• Native to Asia, Europe, and Northern Africa
• Introduced as livestock fodder and honeybee forage

Management techniques:

• Frequent mowing over a few years
• Replanting a cleared area with a native grass after a year of mowing

Japanese Knotweed, Fallopia japonica

• Robust, tall, perennial herb
• Hollow stems that range from reddish-green in the summer to brown-red in the winter
• Small, white flowers in late summer

• Spreads through re-establishing living fragments with soil contact and from rhizomes in the roots
• Native to Eastern Asia
• Introduced as an ornamental herb and for erosion control

Management techniques: 

• Repetitive cutting of younger stands during the growing season for several years
• Smother with heavy landscaping cloth, erosion control fabric, or old carpet for up to 10 years

Properly dispose of all discarded plant material

Wild Parsnip, Pastinaca sativa

• Tall, biennial herb
• Flat topped umbels of small yellow flowers
• Member of the carrot family

• Spreads by seed via wind dispersal or in mulch, hay, and straw along transportation corridors on farms
• Native to Eurasia
• Introduced as a cultivated root crop

Management techniques:

• Digging and gouging patches with the intent to cut off the plants from the taproot
• Timed mowing to prevent seed production or regrowth

Beware of sap! Can cause dermatitis when in contact with skin and sunlight

Purple Loosestrife, Lythrum salicaria

• Robust, perennial herb
• Long crowded spikes with pink-purple flowers that bloom in mid to late summer
• Grows in wetlands and long shorelines

• Spreads by seed via water dispersal and in sediment movement
• Native to Europe and Asia
• Introduced as an ornamental plant and potentially as a contaminant in livestock bedding and wool

Management techniques:

• Digging out small plants by the roots
• Repetitive cutting or hand-pulling during the growing season before flowering for several years

Yellow Iris, Iris pseudacorus

• Robust, perennial forb
• Large yellow flowers that bloom from May until July
• Sword-like, flattened leaves

• Spreads by rhizome fragments and seed. Rhizomes can survive dry for months and moist ones can live for up to 10 years
• Native to Europe, Western Asia, and North Africa
• Introduced as an ornamental flower

Management techniques:

• Digging up plants and repetitively removing them for several years 

Properly dispose of all discarded plant material

Common Reed (Phragmites), Phragmites australis

• Tall, perennial grass
• Fluffy seed heads that range from brown-purple to light tan as the seasons progress
• Interconnected mass of roots and shoots, leading to dense stands on shorelines

• Spreads by seed and by rhizome fragments. Can sprout from any rhizome fragment
• Native to Europe
• Introduced accidentally from international sea travel

Management techniques:

• Cut small patches repeatedly for several years
• Difficult to manage in large quantities without a consistent labor force

Garlic Mustard, Alliaria petiolata

• Biennial herb 
• Grows flowering stems in its second year
• Leaves smell like garlic when crushed

• Spreads by seed via water, sediment erosion, and animal fur
• Native to Europe
• Introduced by European settlers for food

Management techniques:

• Hand-pulling individual plants
• Repetitive mowing during the growing season, particularly in early spring since it will leaf out early like other invasives

Properly dispose of discarded plant material the second year of growth to prevent seed dispersal

Perennial Pepperweed, Lepidium latifolium

• Perennial, multi-stemmed herb
• Small, white flowers in dense clusters near stem tips
• Adaptable roots that can grow deep or creep along the surface depending on growing conditions

• Primarily spreads by seed dispersal but can spread from root fragments
• Native to Southeastern Europe and Southwestern Asia
• Introduced as a contaminant in agricultural seeds

Management techniques:

• Hand-pulling or digging out young plants 
• Setting livestock to graze an area
• Consistent mowing during the growing season

​Properly dispose of all discarded plant material