Earth Matters: Invasive Vine Patrol

by Glenn Sungela, Partner at Lower Hudson Partnership for Regional Invasive Species Management

The Village of Piermont’s Community Cleanup on May 4 was about more than removing trash. This year, resident Erica Lockwood brought her freshman and sophomore biology students from Eastchester High School to remove invasive plants along Piermont Pier.

As Erica explained:

Invasive species threaten the biodiversity and stability of an already established food web. They outcompete the native organisms and often don’t have predators. Human introduction (either intentional or accidental) is the main cause of this destruction. However, we can help in a small way by removing them when possible, to restore order.

The invasive plant species targeted by the students were oriental bittersweet (Celastrus orbiculatus), Japanese honeysuckle (Lonicera japonica), porcelain berry (Ampelopsis glandulosa ), garlic mustard (Alliaria petiolata ), and mugwort (Artemisia vulgaris ). Fortunately, the rainy spring left the ground soft, allowing most of the underlying root systems to be removed.

Students wasted no time pulling invasive herbaceous plants and cutting invasive vines.
Photo: Glenn Sungela

Of these invaders, two of the most common (and harmful) are oriental bittersweet and Japanese honeysuckle. Anyone who has traveled along the New York State Thruway and other open roads has most likely seen these species wrapped around trees and just about anything else they can cling to and climb up.

Congratulations to Earth Matter’s author Susan Hellauer, the recipient of the 2019 Rockland Sierra Club and 350.org Environmental Hero award.

On the most unwanted invasive list: oriental bittersweet

Oriental bittersweet is especially harmful to our local ecosystem because:

• it wraps itself around trees, preventing natural growth;
• when it reaches the top of the canopy it spreads outward, blocking the sun, which eventually kills the native tree;.
• it makes trees top-heavy, causing them to fall down during heavy winds—especially evergreen trees, because of their shallow root systems;
• birds rely on plant berries for nutrition and to store fat for migration and the winter season. Oriental bittersweet’s berries have far less nutrition and fat than berries of native plants, so not only is bittersweet destroying native plants, it is harming wildlife.

Oriental bittersweet choking a tree along the Piermont Pier. Photo: Glenn Sungela

You can identify oriental bittersweet in several ways:

• It twines around tree trunks, branches, and other vines, including itself.
• Its leaves are shiny, round, feel waxy, and alternate on a stem.
• The grey bark starts off smooth, and becomes rougher and pitted as it grows. (Stems grow up to 6” and more in diameter.)
• In the fall, plants have abundant red and orange berries.

Mature bittersweet . . . . . . . . . . . . Bittersweet leaves . . . . . . . . . . . . . . . . . and berries. Photo credits: 1. Zefram via Wikimedia Commons; 2. Chris Evans, University of Illinois; 3. University of Illinois

Chemical or bio-agents are not needed to control oriental bittersweet.  A best practice is to cut the vine twice, once low to the ground and once shoulder or chest height. This is done for three reasons: first, so the area under the tree looks neat; second, so you can see from a distance the vines were cut; and third, so that regrowth, if it happens at all, is detected easily and controlled quickly.

As tempting as it may be, vines should not be pulled down. Pulling them damages the native tree, and you never know what might come down with them–think a large, dead branch. If you have the time and energy, pull up as much of the underlying roots as possible. But be warned that bittersweet’s roots can travel several yards.

Oriental bittersweet was no match for these students. Photo: Glenn Sungela

Another eco-enemy: Japanese Honeysuckle

Japanese honeysuckle also harms native vegetation by taking over and crowding out native plants. It, too, can be identified in several ways. The woody vine runs on the ground until it finds something to climb up and twine. Its leaves are opposite one another, small, simple, and usually smooth-edged. When it blooms, the flowers are usually white, or sometimes yellow.  As they thicken, the light-green colored stems become shreddy.

Japanese honeysuckle in early Spring . . . . . . . . . .and mid-Spring in bloom. Photos: 1. Glenn Sungela; 2. Chris Moorman

Best practices for controlling Japanese honeysuckle are the same as for oriental bittersweet: Cut twice, once low and once high, pull out as much of the root system as possible, and monitor for potential regrowth. But do not pull the leftover vines from the native plant. They, too, will eventually wither away and fall to the ground on their own.

Join the fight!

Erica Lockwood’s Eastchester High School students’ work added to a segment of the Pier adopted by Glenn Sungela in collaboration with Dan Sherman, Chairman of the Piermont Parks Commission, Piermont’s Commissioner of Parks, and with support by the Village Mayor and Board of Trustees. The segment starts at the beginning of the Pier and extends 100 feet on the north side of Ferry Road toward the Hudson River. Chairman Sherman also cleared invasive plants along the Pier, concentrating on the path to the dog run.

Please help improve our sustainability and biodiversity by stopping the spread of invasive species. Stay tuned for more articles on invasive plant volunteer events, as well as information on invasive shrubs, trees, herbaceous plants, invasive aquatic plants, and invasive animals and pests.

Additional resources:

• New York Invasive Species Information. In 2015, New York State enacted legislation under the Department of Environmental Conservation that recognized the threats posed by invasive plants and animals and identified several species which are now prohibited. The state also established an online clearinghouse that provides science-based information, innovative tools, news, and events for coping with biological invaders in New York.

• Lower Hudson Partnership for Regional Invasive Species Management. One of the ways New York helps to manage invasive species is by establishing partnerships for invasive species management, or PRISMs. The eight PRISMs across the state comprise land stewards, conservancies, local parks departments, and others dedicated to controlling invasive species in their regions.  The Lower Hudson PRISM based at the New York-New Jersey Trail Conference Headquarters in Mahwah, New Jersey is very active in coordinating invasive species management in our region.

• For more information on how invasive plants harmfully interact with ecosystems, watch this video  by Dr. Doug Tallamy, Professor of Entomology at the University of Delaware. Insights on birds and native vs. non-native plant berries starts at the 41:20 mark.

• Anyone interested in helping to restore the Piermont Pier to its natural vegetation and beauty can contact Glenn Sungela at gsungela@yahoo.com. 

Students standing behind the fruits of their labors. Their shirts read “Save the Earth. It’s the only planet with (pizza, chocolate tacos, coffee)”. Photo: Glenn Sungela

Learn more:

• “Beware Invasive Plants” (7/9/16, Nyack News and Views)
• “Rockland Lake’s Hidden War” (10/15/16, Nyack News and Views)
• “Native Plant Gardening” (6/4/16, Nyack News and Views)

Earth Matters, a weekly feature that focuses on conservation, sustainability, recycling and healthy living, is sponsored by Maria Luisa Boutique, Strawtown Studio, and Summer Play Camp at Blue Rock School. Read Earth Matters every Wednesday on Nyack News And Views, or sign up for the Earth Matters mailing list.