Common Buckthorn, Rhamnus cathartica

• Perennial, deciduous shrub
• Small, white-green flowers clustered at leaf bases during bloom

• Spreads by seed, which are viable for 2-6 years
• Native to Europe and Asia
  
• Introduced to US for hedge-rowing

Management techniques:

• Hand-pulling small plants and seedlings
• Repetitive cutting during growing season for several years
• ​Consistent mowing

Japanese Barberry, Berberis thunbergii

• Perennial, deciduous shrub
• Sharp, spiney branches that make management challenging
• Red, oblong berries in summer

• Spreads by seed, which are viable for 1-5 years
• Native to Japan and Asia
  
• Introduced to replace common barberry

Management techniques:

• Hand-pulling small plants and seedlings
• Repetitive cutting during growing season 
• Consistent mowing

Beware of thorns!

Autumn Olive, Elaeagnus umbellata

• Perennial, deciduous shrub
• Silvery, shiny leaves and aromatic white-yellow flowers
• Yellow to orange to red berries

• Spreads by seed via birds and mammals
• Native to China, Korea, Pakistan, and Japan
• Introduced as an ornamental plant for gardens and cover

Management techniques:

• ​Hand-pulling small plants and seedlings
• Repetitive cutting during growing season
• Consistent mowing

Multiflora Rose, Rosa multiflora

• Perennial, deciduous shrub
• Thorny branches that spread and tangle with surrounding ecosystem
• white to pale pink flowers and red rose hips

• Spreads by seed, which are viable for up to 20 years, and by twig tips rooting with soil contact
• Native to Japan and Asia
• Introduced for use as an ornamental plant, living fences, and erosion control

Management techniques:

• Hand-pulling small plants and seedlings
• Repetitive cutting during growing season
• Consistent mowing 

Beware of thorns and properly dispose of cut material!

Tatarian Honeysuckle, Lonicera tatarica

• Perennial, deciduous shrub
• Sweet-scented pink flowers 
• Red, juicy berries that ripen by summer
• One of multiple invasive honeysuckle varieties

• Spreads by seed via birds and mammals
• Native to China
• Introduced as an ornamental shrub and windbreak

Management techniques:

• Hand-pulling small plants and seedlings
• Repetitive cutting during growing season
• Consistent mowing

Black Locust, Robinia pseudoacacia

• Fast growing, deciduous tree that can reach from 40-100 feet tall
• Usually has white, pea-shaped flowers in blooming season

• Spreads by seed via birds and mammals and by suckering, which establishes large clones
• Native in Southeastern U.S. (primarily Appalachia, Pennsylvania and Southward)
• Introduced to Maine because of its dense wood, ideal for lumber

Management techniques:

• Hand-pulling seedlings
• Pulling saplings with weed levers
• Repetitive cutting for larger trees

Norway Maple, Acer platanoides

• Deciduous tree that grows to anywhere from 40-60 feet tall
• Leaves characteristic to that of native maples, with stems oozing white sap to differentiate 
• Holds leaves later in autumn

• Spreads by seed via small mammals and by wind
• Native to Europe and Eastern Asia
• Introduced to US as an ornamental tree

​Management techniques:

• Hand-pulling seedlings
• Pulling saplings with weed levers
• Repetitive cutting for larger trees

European Alder, Alnus glutinosa

• Deciduous, fast-growing tree that reaches about 30-50 feet tall
• Shallow, dense roots with nitrogen fixing nodules
• Female catkins (seed pockets) become woody and tough in fall

• Primarily spreads by seed via wind and water, but can also spread by suckering 
• Native to Europe and Western Asia
• Introduced for firewood and mistaken for speckled alder (Alnus incana) in wetland restorations

Management techniques:

• Hand-pulling seedlings
• Pulling saplings with weed levers
• Repetitive cutting for larger trees

Tree of Heaven, Ailanthus altissima

• Deciduous, fast-growing tree that can reach 50-90 feet tall
• Large terminal clusters of flowers during blooming season
• Pale gray, smooth bark

• Spreads via seed (prodigiously!) via wind and by clonal growth through root sprouting
• Native to China
• Introduced as an ornamental tree

Management techniques:

• Hand-pulling seedlings
• Pulling saplings with weed levers
• Repetitive cutting for larger trees

Beware of sap! It can cause dermatitis and other skin reactions