Healthy Forests

Top Invasive Plants Forest Owners Should ID, and Remove

Help New York birds by creating healthier woodland habitat.

Native plants provide the most habitat value to wildlife, from backyard birds to those found in the depths of our largest forests. That’s because they support all or part of the life cycle of our native insects, which are the primary food source for the majority of forest bird species during the spring and summer breeding season.

By managing your property to provide a diversity of native trees, shrubs, vines, and herbaceous plants, you can offer more nutritious food options—including fruits, seeds, and nuts—for an incredible variety of forest birds.

The key, of course, is knowing the difference between native vegetation, invasive native plants, and non-native invasives.

An ID Guide to Invasive Forest Plants

Quick fact! Even certain native species, like American beech, can dominate your forest understory and prevent healthy forest regeneration.

Ideally, you will want to work with a forester and/or a licensed applicator to plan your next steps! Fill out our Landowner Assistance Form so we can help get you connected.

HONEYSUCKLE
(Multiple species, but mostly tartarian in forests upstate)

Honeysuckle. Photo: Kimm/Flickr CC BY-NC-ND 2.0

Honeysuckle is a non-native invasive perennial shrub that can reach 8-10’ in height. The leaves are green and have an oval shape. This species will produce fragrant white flowers and dark red berries in the spring.

WHERE TO FIND IT
Abandoned fields, forest edges, disturbed areas and open canopy forest. Tolerates both sun and shade.

METHODS TO CONTROL IT
Mechanical- Hand Pulling: Hand pulling is only effective in areas of very light infestation. Take extra care not to disturb the soil more than necessary as this may expose soil for the seeds to germinate.

Mechanical- Stem: Repeatedly cutting the stem flush with the ground multiple times during the growing season may be enough to reduce the density of honeysuckle in some areas.

Chemical- Foliar Herbicide: Apply an herbicide (1% glyphosate solution) to seedlings by spraying the foliage. In the case of larger, more established individuals, cut the stems flush with the ground and apply an herbicide to the stump (2-3% glyphosate).

BUCKTHORN
(Common and glossy)

Buckthorn. Photo: Lorianne DiSabato/Flickr CC BY-NC-ND 2.0

A non-native and invasive deciduous shrub or vine that can reach 25’ in height. The leaves are dark green, oval and glossy on the top. Groups of small black berries similar in size to wild blueberries can be found on this plant from July to mid-October. This species shows yellow-green flowers in the spring from April through June.

WHERE TO FIND IT
Forests, forest edges, fallow fields, meadows, disturbed areas.

METHODS TO CONTROL IT
Mechanical- Hand Pulling: Hand pull by the base of the stem and be sure to remove the entire root system. Make sure the exposed root system is not left in contact with the ground after removing to prevent re-rooting.

Mechanical- Cut Stump: Cut plants at the stem close to the ground any time of the year. Wrap the exposed stump with burlap or thick plastic and secure with twine or a thick zip tie. This should prevent any new stump sprouts from developing in the spring. Check periodically for new growth.

Chemical- Cut + Herbicide: Cut the stem 4” above the ground. Apply an herbicide (18-21% glyphosate solution) directly to the stump within an hour of cutting. This has the most beneficial impact in the late summer through winter when more nutrients are going to the root system.

Chemical- Foliar Herbicide: Spray an herbicide (2% glyphosate or triclopyr solution) to the plants entire leaf surface. This work should be contracted through a licensed applicator during the fall for the best results.

AMERICAN BEECH

American Beech leaves. Photo: Sheldon Community Forest/ Flickr CC BY-SA 2.0 | American Beech bark disease. Photo: Joshua Mayer/Flickr CC BY-SA 2.0

A native but interfering species given its ability to proliferate in both shade and sun as well as its tendency to aggressively root sprout. This species is also affected by American beech bark disease, which will kill the host tree- resulting in more suckering from the remaining root system.

WHERE TO FIND IT
Forested areas throughout NY.

METHODS TO CONTROL IT
*Mechanical treatments are only viable in areas of low infestation

Mechanical- Hand Pulling: Small plants can be pulled in areas where there is not heavy beech density. When pulling make sure to remove as much of the root system as possible.

Mechanical- Girdling: Girdling a tree can be done with a chainsaw, ax or flame torch. A cut is made just inside the bark of the tree to cut off nutrient flow between the roots and tops of the tree. (*Cut treatments should be avoided without a companion chemical treatment. American beech has the ability to stump sprout and the beech density issue will be compounded by cutting stems without treatment.)

Chemical- Hack n Squirt or “Frill” treatment: Expose the inner bark by making a cut with a hatchet and apply a small amount of concentrated herbicide (20%-50% glyphosate or imazapyr). This can also be carried out by drilling a hole into the stem and applying the herbicide to the hole.

Chemical- Cut Stump Treatment: Cut the stump flush with the ground and apply an herbicide (glyphosate or triclopyr) directly to the stump to kill the root system. This treatment can be applied up to 72 hours following a cut.

Chemical- Basal Bark Treatment: Apply herbicide with a backpack sprayer on the lower 12-15” on the trees stem to chemically girdle it.

NOTE: some American beech is resistant to beech bark disease, and care should be taken to protect and retain these trees. If you are unsure about beech bark disease on your property, please contact a forestry professional for an assessment. Where it is healthy and mature, American beech trees are an important source of hard mast for birds and other wildlife.

HAY-SCENTED FERN

Hay-scented Fern. Photo: Nicholas A. Tonelli/Flickr CC BY 2.0

A native but interfering species, hay-scented fern has yellowish green fronds and smells like hay. This species grows in dense mats near the forest floor outcompeting any desirable vegetation for light and other nutrients.

WHERE TO FIND IT
This fern is most commonly found in canopy openings in the forest but is also prominent in shaded, damp environments.

METHODS TO CONTROL IT
Mechanical- Hand Pulling: Pull the fern and the entire root system in areas of light infestation. Take care not to excessively disturb the soil so that adjacent rhizomes are not broken, resulting in more spreading.

Mechanical- Mowing: Mow with either a brush hog or weed trimmer twice during the growing season, once in June and again in August.  Repeat this method the following year. This will not eradicate the species but it will great reduce its density.

Chemical- Foliar Herbicide: Apply an herbicide spray (glyphosate) targeted at the ferns fronds. This method is the most trusted for complete eradication of the fern.

JAPANESE BARBERRY

Japanese Barberry. Photo: Matthew Beziat/Flickr CC BY-NC 2.0

Small deciduous shrub that ranges from 2 to 8’ in height. Leaves are green and shaped like long paddles. Pale yellow flowers hang off the stems of branches from mid spring to early summer. Small bright red berries are also noticeable in the summer months.

WHERE TO FIND IT
Forests, open woodlands, wetlands, floodplains and meadows.

METHODS TO CONTROL IT
Mechanical- Hand Pulling: Pull small plants by the stem and be sure to extract the entire root system. Make sure the exposed root system is not left in contact with the ground after removing to prevent re-rooting.

Mechanical- Cut Stump: Cut plants at the stem close to the ground in the fall or winter. Wrap the exposed stump with burlap or thick plastic and secure with twine or a thick zip tie.  This should prevent any new stump sprouts from developing in the spring. Check periodically for new growth.

Chemical- Cut + Herbicide: Cut the stem 4” above the ground. Apply an herbicide (18-21% glyphosate solution) directly to the stump within an hour of cutting. This has the most beneficial impact in the late summer through winter when more nutrients are going to the root system.

Chemical- Foliar Herbicide: Spray an herbicide (2% glyphosate or triclopyr solution) to the plants entire leaf surface. This work should be contracted through a licensed applicator during the fall for the best results.

*Chemical treatment methods were sourced from Vermont Invasives.