Amur Honeysuckle (Lonicera maackii)

Description:  
Native to eastern Asia, Amur honeysuckle is a multi-stemmed shrub which grows up to 15 feet tall with simple, opposite leaves. It produces white flowers in the spring and has bright red berries in the fall. It is very easy to identify in the fall because it retains it leaves long after other native species. Amur honeysuckle was introduced in the United States in the late 1800’s as a new ornamental species and later promoted for soil conservation purposes.

Negative effects:
Research has shown that honeysuckle rapidly invades disturbed areas and prevents native species from growing. When honeysuckle persists in a forest, the forest understory becomes dominated by the shrub and contains many fewer tree seedlings, saplings, and wildflowers.

Control:
Honeysuckle is controlled in several ways. In open areas or along the edges of forest, honeysuckle is mechanically removed using a 6 ton, forestry mulching machine. During the following season, many of the stems will resprout and are then treated with an herbicide to prevent further growth. Honeysuckle growing along paths or within the forest must be controlled in a way that avoids damaging other forest plants. To accomplish this, an herbicide treatment is applied in the fall when other forest plants have lost their leaves and are dormant. Smaller shrubs are treated by spraying a 1% glycophospate solution on the leaves (this is the active ingredient in Round-Up). Large shrubs are first cut back, and then the stump or the base of their stems is treated using a 15 % solution of herbicide.

Description:
Lesser celandine is a low-growing, yellow-flowered wildflower distinguished by glossy, heart-shaped leaves. It is one of the first plants to bloom in the spring in moist woods and floodplains. It is a native of Eurasia and was introduced as an ornamental plant.

Negative effects:
Lesser celandine rapidly forms a dense mat choking out native species, especially spring wildflowers.  New locations are invaded through the release of “bulblets” (small bulb-like structures) that are dispersed by rain and water and rapidly grow into new plants.

Control:  
A 3-5 % solution of glycophosphate (the active ingredient in Round-Up) with a surfactant (an ingredient that helps the solution adhere to the leaves) is applied with a sprayer as soon as the plants appear in the spring.  Early treatment avoids harming native plants that emerge slightly later.

Description:
Garlic mustard is a biennial plant. Biennial plants have a two year life-span, producing seed only in the second year. In year one, garlic mustard plants are low-growing rosettes with triangular to kidney-shaped leaves. In year two, they grow 1 to 3 feet tall and produce clusters of ¼ inch white flowers with 4 petals. The leaves have a distinct garlic odor when crushed. Look for their narrow seed pods called siliques.

Negative effects:
This plant rapidly invades woodlands and disturbed areas by producing an extremely large number of seeds. The seeds are transported to new locations by water, animals, or as inadvertent hitchhikers on the shoes and clothing of people.

Control:  
Plants are carefully sprayed in the fall with a weak glyphosate solution (the active ingredient in Round-Up). Some populations of garlic mustard in the MetroParks have been reduced by a fungus called powdery mildew.  Infected plants will appear to be covered in white powder.