Hell’s Half Acre Restoration

Hell’s Half Acre, a 7.5 acre section of “urban wild” along the Charles River in Cambridge, is an ecological and social asset to the surrounding community. However, the area is critically overwhelmed by invasive plants.

Through a unique three-year project that uses best practices to remove invasive plants, we are partnering with the Department of Conservation and Recreation (MassDCR) to restore the area. These efforts will establish native vegetation, increase wildlife habitat, and educate the public.

Hell’s Half Acre is great place to walk, bird watch, and enjoy nature.

“During many years I walked there [Hell’s Half Acre] often and so did a lot of other people.  There were trees, grass, a lot of mixed vegetation, minute watercourses, and so much small wildlife…”

– Bernard DeVoto, 1955
Hell’s Half Acre, Mass.


The restoration will be performed by Land Stewardship, Inc. and include manual invasive plant removal, targeted herbicide application, and replanting with native species. Since invasive plants and their seeds can persist beyond initial control efforts, treatment is planned for three years, and maintenance of the site will be ongoing.

We will also enlist our Conservancy Volunteers, who will be trained in manual invasive plant removal and natives replanting. By involving the community, we will promote stewardship and provide valuable hands-on volunteer opportunities.

Our Hell’s Half Acre restoration work addresses invasive plants, including phragmites, Japanese knotweed, and buckthorn. Learn more about the work by reading the project proposal.


The herbicide application methods selected for Hell’s Half Acre are designed to limit and contain herbicide to the stands of invasive species and the project has been carefully reviewed and permitted by MassDCR and Cambridge Conservation Commission. To confirm that the herbicide is not being transferred to the river in harmful amounts, we have also partnered with Northeastern University and Professor Loretta Hernandez to develop a monitoring plan.

Professor Hernandez and her team have deployed passive water samplers upstream and downstream of Hell’s Half Acre. The samplers are designed to collect data over time and will determine if and how much of the active chemicals have been added to the Charles. The CRC does not take the use of herbicide along the Charles River lightly, but recognizes it is a necessary tool in the restoration of this important stretch of riverfront.

Passive water samplers have been installed in the Charles River.
A passive water sampler installed under the Elliot Bridge.


  • Dept. of Conservation and Recreation Partnership Matching Funds Program
  • City of Cambridge Community Preservation Act Funds
  • Bilezikian Family Foundation
  • Carol and Paul Fremont-Smith 
  • Cambridge Plant & Garden Club
  • Harvard Business School
  • Lawrence and Lillian Solomon Foundation
  • RBC Foundation – USA  

Interested in supporting our restoration work at Hell’s Half Acre in Cambridge? Contact Laura Jasinski, ljasinski@thecharles.org.