Invasive Plants

Invasive Plants

Invasive plants are non-native species that have become weed pests by growing aggressively and displacing native plants.  Outside of their natural range, these plants lack the natural controls such as insects. diseases, and herbivores that would keep them in balance within their ecosystem.

Second to habitat loss, invasive plants are the greatest threat to the survival of native plant species and the animals that rely on them.

Control Methods

Pull out by hand, including roots.

Pull out by hand, including roots.

Elevate pulled or dug plants and secure to prevent falling and re-rooting.

Bag plants before seed disposal and place in trash.

Keep at it! Success will require repeated efforts.

Stomp down distbured soil with your foot.

Call municipality,

724-327-2100.

GarlicMustard second year.jpg

Garlic Mustard (Alliaria petiolata)

Garlic mustard is a biennial.  First year plants form ground rosettes of leaves that remain dark green through winter and have a garlic odor when crushed.  second year plants bear 12" - 48" high stems with white flowers in May followed by branched slender seedpods.

Burning Bush  (Euonymus alatus)

Burning bush (also known as winged euonymus) is a shrub reaching 20 feet in height and width.  Gray-brown stems with corky wings or ridges bear opposite leavs that turn scarlet in fall and purplish capsules that open in the fall to expose red or orange seeds.

if small

if big

Bush Honeysuckle (Lonicera spp.)

Bush honeysuckles are upright shrubs reaching heights of 16 feet.  Thornless stems bear opposite leaves and fragrant tubular flowers in May or June followed by showy orange or red berries in pairs of clusters.

if small

if big

Barberry        (Berberis thunbergil, Berberis vulgaris)

Barberry is a shrub with arching branches bearing sharp spines, desnse clusters of small leaves, and small yellow flowers in May followed by bright red oblongg berries.  Cut stems and roots are yellow.

Caution, thorns!

if small

if big

Japanese and Giant Knotweed

(Polygonum cuspidatum,and Polygonum sachallnese)

Japanese and giant knotweed are perennial plants with long rhizomes that create dense thickets reaching 12 feet in height.  bamboo-like clumps of smooth hollow stems with alternate leaves bear white flowers in late summer.

Japanese Honeysuckle Vine  (Lonicera japonica)

Japanese honeysuckle is a perennial vine. Twining stems, which will girdle and kill other vegetation, hold oval or oblong opposite leaves and fragrant tubular flowers in spring and early summer, followed by small black fruits.

if small

if big

Japanese Stilt Grass (Microstegium vimineum)

Japanese stilt grass is an annual grass reaching 1 to 3 feet along trails, ditches, stream banks and floodplains.  asymmetrical leaves hold a silvery midrib,

Tree of heaven (also known as stinking sumac) is a tree reaching 80 feet.  It resembles sumac, black walnut, and butternut.  Smooth leaflets have one 'tooth' at the base and give off the taste of rancid peanut butter when crushed.

Caution, contact can irritate skin!

Tree of Heaven      

(Allanthus atissima)

if small

if big

Multiflora rose is a spreading rose shrub reaching 9 feet high and 18 feet wide that forms dense thickets.  Upright arched thorny canes bear fragrant flowers folllowed by bright red rose hips that may persist through winter.

Caution, thorns!

Multiflora Rose

(Rosa multiflora)