Report to CPC_2022-08-25_Contract_FINAL.pdfFINAL REPORT TO THE COMMUNITY PRESERVATION COMMITTEE
FROM THE BROAD BROOK COALITION
AUGUST 2022
Goals: Broad Brook Coalition continued its efforts to control or eradicate several species of
invasive plants in the Fitzgerald Lake Conservation Area (FLCA) frrom 2019-2021 with funding
awarded by the Community Preservation Committee. The long-range goal of this work is to
preserve the native habitat of the FLCA by controlling the proliferation of a variety of invasive
plants as well as to discourage their resurgence in the future through periodic monitoring. As in
the past, the primary target species were glossy buckthorn (Rhamnus frangula) in Cooke's
Pasture and its periphery, black swallow-wort (Cynanchum louiseae) in Cooke's Pasture, and
spotted and brown knapweeds (Centaurea maculosa and Centaurea jacea) in Cooke's Pasture
and on the Fitzgerald Lake dam. Small amounts of several other invasive plant species were
also targeted.
General Approach: Cooke's Pasture consists of approximatey seven acres and is maintained
as open shrubland by periodic mowing. Owing to work performed over the past several years,
we no longer have the dense concentrations of invasive plants in the pasture and adjoining
areas that we faced fifteen years ago and estimate that the populations of the targeted plants
has been reduced by over 95% compared to their prevalence in 2008--2009 when control efforts
were initiated. Rather, they are now dispersed, requiring the selective targeting of individual
invasive plants in a background of native plants. Land Stewardship, Inc. (LSI)), which has
carried out this work, has proven to be very adept at limiting herbicide treatment to target plants
without causing collateral damage to surrounding grasses, flowers and native shrubs. Access to
Cooke's Pasture was improved in 2020 by the removal of several large rocks on the entrance
pathway by RCW Landscape Construction
Black Swallowwort in Cooke's Pasture. Black Swallowwort is an invasive vine that can
compete with native vegetation, replacing grasses, goldenrod and milkweed by monotypic mats
that negatively impact insects and animals such as turtles and birds that depend upon a healthy
grassland or shrubland habitat. A small patch of black swallowwort was discovered in the
central lobe of Cooke's Pasture in 2012. Sporadic herbicide treatment failed to prevent this plant
from going to seed and the infestation expanded to roughly one-quarter of an acre. A systematic
effort to eradicate black swallowwort, initiated in 2016, has reduced the size of the infestation to
less than one-tenth of an acre by treatment of individual plants with herbicide. The small number
of plants found in 2019 were spot-sprayed with Vastlan (a triclopyr derivative) and Escort XP
(metsulfuron methyl). In 2020, there was no swallowwort in the pasture, though a dozen plants
were discovered in the adjacent woods and spot-sprayed with the Vastlan-Escort mixture. In
2021, the few remaining plants were treated with herbicide. We will continue to monitor this area
in the future to make sure that no swallowwort persists.
Knapweed in Cooke's Pasture and on the Fitzgerald Lake Dam. LSI crews targeted spotted
and brown knapweeds in Cooke's Pasture and on the dam each summer of the contract. At the
same time, they also treated smaller amounts of other invasive plants, including bittersweet,
multiflora rose and exotic honeysuckle. Knapweed plants were treated with a low-volume foliar
spray of Vastlan and Streamline (sulfonyl urea). In general, knapweed seems to be under good
control: their abundance was low throughout and found mostly along field and trail edges. This
is good news as, If left unchecked, knapweeds can overtake grassy fields and maintain their
predominance through the release of products that adversely affect the growth of native plants.
We will endeavor to keep these plants under satisfactory control in the future through close
monitoring and spot herbicide treatment.
Buckthorn in Cooke's Pasture and the Forested Perimeter. Roughly eight years ago, it
became evident that mature glossy buckthorn trees growing in the ~9-acre forested buffer zone
between Cooke's Pasture and the Broad Brook marsh provide an abundant source of seeds
that can spread and give rise to new buckthorn growth in the pasture. Some of these trees were
treated with herbicide in 2011 and 2013, but coverage was not complete and a number of large
buckthorns persisted in the periphery. In March 2016, buckthorns in the buffer zone were
systematically cut in preparation for subsequent herbicide treatment.
LSI crews treated buckthorns in Cooke's Pasture and its forested buffer zone each summer with
either Rodeo, Vastlan, Streamline or Garlon 3A using a targeted, low-volume foliar spray. In
2020, the crew returned twice to complete the suppression of plants on the forest periphery as
well as in the pasture. A significant number of small buckthorns were also noted on the adjacent
forest floor at that time. In 2021, a crew from LSI came out in December to remove large
buckthorns remaining on the forest edge with chain saws and brush saws, and the stumps were
treated with Rodeo using the cut-stem approach. At that time, the crew commented that there
were still large buckthorns between the southern pasture edge and the Broad Brook marsh. It is
evident that buckthorn infestation in this area will persist for some time and will need more effort
to eradicate.
Other Efforts to Control Invasive Plants in the FLCA. In each of the past three years,
volunteer crews removed garlic mustard and multiflora rose by hand at the North Farms Road
entrance to the FLCA, cut back multiflora rose, bittersweet, winged euonymous, and other
invasive plants along Boggy Meadow Road, and pulled large amounts of water chestnut from
Fitzgerald Lake. At the same time, follow-up herbicide treatment of Japanese knotweed on
Marian Street and of Phargmites in the Broad Brook marsh were carried out by O'Gara
Landcare with funding from the BBC.
August 25, 2022
Robert A. Zimmermann
President
Broad Brook Coalition
BUDGET SUMMARY
Expenditures in 2019:
Budgeted Expended
Landscape Stewardship, Inc.
Black swallowwort control in $ 250 $ 250
pasture
Buckthorn control in pasture 1,600 1,600
and forest perimeter
Knapweed control in pasture 600 600
and on dam
Subtotal: 2,450
Expenditures in 2020:
Landscape Stewardship, Inc.
Black swallowwort control in 250 250
pasture
Buckthorn and knapweed control in 2,000 2,000
pasture, forest perimeter and dam
Subtotal: 2,250
Expenditures in 2021:
Landscape Stewardship, Inc.
Black swallowwort control in 250 250
pasture
Buckthorn and knapweed control in 2,000 2,000
pasture, forest perimeter and dam
Subtotal: 2,250
Total: $ 6,950 $ 6,950