With part of our mission being to sustain the natural green space of the Charles River Esplanade through ecological restoration and stewardship, the Board and Staff of the Esplanade Association have embarked on a journey to improve key parts of the park’s iconic shoreline by removing invasive plant species, allowing native species to return. Conducted in partnership with the Massachusetts Department of Conservation and Recreation, and with the approval of the Boston Conservation Commission and the Massachusetts Department of Environmental Protection, this project will result in an improved land and water environment on the Esplanade as well as restored habitat for native pollinators, birds, and other wildlife.
The project began with a 2017 – 2018 pilot project and study report of invasive plant species on the Esplanade, conducted by SOLitude Lake Management and with generous support from the Merck Foundation. The pilot project examined the impacts of different treatment strategies on a selection of non-native plant species found along the riverbanks of the Esplanade, and the results were compiled into the subsequent study report. These non-native species, including nuisance plants such as common reed (phragmites australis) and Japanese knotweed (fallopia japonica), dominate the riverbank, resulting in damage to the native ecosystem and impairment of recreational activities.
The project tests were conducted in October of 2017, with several plots set up to examine different physical and chemical plant management strategies. For our most aggressive problem species, common reed, the most effective treatment was found to be a combination of both physical and chemical management strategies — cutting the plant by hand, then carefully applying an herbicide mixture on the cut stems of the plant.
The study report detailing the findings was published in 2018, and can be viewed here.
In 2019, the Esplanade Association worked to have the pilot project’s environmental permitting period extended to allow us to continue the work that the study initiated. The project’s Order of Conditions, issued by the Boston Conservation Commission, was extended until October 2022 with the objective of carrying out the study’s recommended treatment program (MassDEP file no. 006-1482).
A recent review of invasive species on the Esplanade revealed few significant patches of Japanese knotweed, but over 2,000 linear feet of common reed along the Esplanade’s banks. See below for maps showing where these invasive species were catalogued by Esplanade Association staff.
These large stands of common reed overwhelm and outcompete native species, while providing little to no nutritional value for pollinators and wetland animals. Additionally, the tall plants block views of the river and Cambridge beyond, robbing visitors of the viewsheds highlighted in the park’s original design.
The removal and eventual eradication of common reed stands throughout the Esplanade will facilitate the return of riverbank plant species that are more beneficial for a healthy and diverse ecosystem, while also improving views and recreational opportunities for the Esplanade’s 3 million annual visitors.
This summer, the Esplanade Association continues towards the project’s goal. The project will involve hand-cutting common reed and Japanese knotweed, and disposing of vegetative debris the same day it is cut at a qualified compost facility.
Japanese knotweed patches along the Esplanade will then be treated with non-chemical methods such as solarizing and re-planting with native species to “crowd out” the knotweed, where possible.
Common reed, however, covers much larger swaths of the Esplanade’s banks, and its eradication requires more aggressive treatment, as recommended in the original 2018 study. After cutting, an herbicide solution will be carefully mixed and applied by hand, by Certified Applicator professionals from our partners at Groundscapes Express, Inc. This precise application method avoids any amount of excess herbicide solution in the water or on non-target plant species.
Herbicide treatment will take place in September 2021. This late summer treatment is timed to weaken the common reed as it enters its dormant period, in hopes that it will not re-emerge in the spring. Any shoots that re-emerge in the spring will be re-treated at that time.
In accordance with our environmental permitting conditions, signage bearing the MassDEP file number (006-1482) will be posted at all treatment sites. Due to the treatment being used and the careful method of application, there will be no water use restrictions at this time.
As the targeted invasive species are treated, the Esplanade Association will work in partnership with the Department of Conservation and Recreation to review appropriate species for possible re-planting sites to restore the shoreline as suitable habitat for native species.
Thank you for your interest!
To learn more, contact Alison McRae, Director of Projects and Planning, at firstname.lastname@example.org.
To support our efforts, visit esplanade.org/donate.