By Duffy Zimmerman
Emerald green leaves brushed against John Carbone’s khakis as he waded through the sea of garlic mustard plants at the Garvies Point Preserve in Glen Cove.
As an employee at the environmental reserve and its accompanying museum, Carbone led a group of nine volunteers on April 27th to remove as much of the weed as possible.
“We preserve the environment the best we can, but sometimes that means we have to remove a lot of stuff, like all the pretty little white flowers behind me,” Carbone said.
Garlic mustard, or Alliaria petiolata, is an invasive species that has spread rapidly in New York, with areas of highest density reported in the Long Island-Metro region, according to the New York iMap Invasives. Named for the distinct odor from its crushed leaves, garlic mustard is believed to have been brought to the United States from its native habitats in Europe and Asia for medicinal and culinary purposes about 150 years ago.
Since that time, garlic mustard has invaded so much area that it poses a threat to native plants and animals. Environmentalists worry that without natural predators to keep it in check, this invasive species will overtake the ecosystem.
“Invasive plants like garlic mustard compete for light, water, nutrients, space, and other resources, and soon choke out native plants and the wildlife that depend on them,” Bill Jacobs, the program manager for Long Island Invasive Species Management Area (LIISMA), said. “Garlic mustard is one of our most common and most destructive invasive plants, depending on where it is located.”
Although Garvies Point employees note that garlic mustard is fairly easy to uproot, its reproductive abilities make eradicating the plant from large plots a difficult task. This particular species is biennial, which means that garlic mustard plants mature over the course of two years. Once the weed has reached maturity, small cross-shaped flowers bloom right next to pods filled with seeds at the top of the plant.
Seed pods on a particularly fertile plant, can produce as many as 7,900 seeds, which can remain dormant in the soil for up to six years. Since the plants have not yet generated seeds by early spring, March and April is the most effective time to remove garlic mustard plants.
“We have noticed much improvement in the areas where we have been pulling,” Veronica Natale, Director at Garvies Point Museum and Preserve, said. Natale added that at least five years of consistent pulling are required to completely clear an area of garlic mustard since the seeds can remain viable for several years. “Unfortunately we don’t always get to every area each year – this is why we need volunteers!”
The volunteers at the Garvies Point garlic mustard pull all had the same goal, but they were in attendance for different reasons. College students like Sean Finn came to the event seeking community service credit.
“I did a lot of library stuff like stocking shelves, but I like being out here, especially in the spring when the weather is nicer,” Finn, a senior at St. Francis College said. “We’re pulling garlic mustard today that smells like garlic. It’s not unpleasant, so that’s nice.”
Another student, Christopher Lim, was helping the environment for a conservation biology class at Hofstra University. Although the garlic pull was simply the event from a list provided by his professor that fit most easily into his schedule, Lim skimmed for the unmistakable white cross-shaped flowers in the high grass of the meadow .
“Since the garlic mustard is an invasive species that is incredibly prolific, they need volunteers to pull as much of it out as possible,” Lim, a biology major, said.
Some of the volunteers that came to the invasive species extermination project on the 62-acre preserve have a vested interest in removing the plant, and have attended similar events in the past. As a long-time environmentalist and retired resident of Sea Cliff, Jean Millspaugh volunteers with a variety of organizations that are combating invasive species.
“I’m trying to help out Garvies Point Preserve, because they need help,” Millspaugh said. “I think it’s everybody’s responsibility to help out and take care of invasive species that we did not want, but are here.”
Other than Garvies Point, Millspaugh works with the North Shore Audubon Society to combat invasive species like garlic mustard on Long Island. Removing invasive species advances this organization’s mission “to promote, protect, and preserve the environment and the birds that inhabit it,” since they can overtake resources upon which insects, and therefore birds, depend.
“Most birds feed their [offspring] insects,” Peggy Maslow, president of the North Shore Audubon Society. “Many adult birds survive on insects themselves and insects depend for their survival on native plants.”
Conservation scientists note that having many different species, or biodiversity, in one area maintains a balance in nature. Garlic mustard and other invasive species can disrupt this balance as they spread throughout the ecosystem.
“Having that biodiversity, it’s kind of one system that’s all linked together,” Luke Gervase, an education and outreach specialist with LIISMA, said. “When you have one plant that’s taking over, it flips that upside-down.”
Garlic mustard plants also practice allelopathy, which means that they secrete chemicals that restrict plants from growing around them. This can wipe out other plants entirely, leaving a monoculture, or area with only one type of plant, in its wake.
“Many native plant species have become locally extinct as a result of invasive monocultures, such as kudzu in swaths of southern U.S. for example, that reduce plant diversity, or the variety of species in a particular region,” Julie Sullivan, author of the Go Native LI blog, said.
Sullivan has been leading efforts to remove invasive plants and restore natives one in the grasslands of Carpenter Farm Park in Huntington. “With diversity, options for survival multiply with different form, structure, nutrition, habitat, etc. However, when a disease hits a monoculture, nothing may survive locally,” she said.
Some recreational environmentalists even caution allowing seemingly harmless invasive species to remain. Without natural predators to keep garlic mustard at bay, hobbyists are observing noticeable change in nature.
“After 32 years of living here in my home in Setauket, [garlic mustard] now appears quite heavily at the front of our property where it only slightly appeared last year and never before that,” Jane Fasullo, the outing program manager for the Long Island Sierra Group, said. “It’s not just one or two species being displaced, it’s the whole environment.”