Roslyn Harbor, NY

Cedarmere Preserve Invasive Species Management & Green Infrastructure Projects

Bioswale & Native Plantings at North Parking Lot

In Spring 2026 Nassau County Soil and Water Conservation District (NCSWCD) Part C Funding supported the design and construction of two bioswales (2,901 sq. ft.) adjacent to a freshwater wetland near the Preserve’s north parking lot, which is vulnerable to runoff and erosion. The project included invasive species and turf grass removal, native plant restoration, and the installation of boulders to redirect runoff into the bioswales.

Arboretum Tags and Invasive Species Removal at Cedarmere Preserve

In 2024 NCWSCD Part C Funding provided support to the Friends of Cedarmere to label over 300 trees at the Preserve with the goal of tagging approximately 51 species of trees, identifying the common and scientific name as well as the region of origin. A tree map was created to indicate the location of trees, accompanied by educational signage about the benefits of native plants. The Long Island Invasive Management Area surveyed the natural area for invasive plants and created a report on plant species in the area. The Preserve worked with NYS DEC staff to remove invasive plants from the pond.

Removal of Invasive Species and Undesirable Vegetation & Hydroseeding with Native Grasses and Wildflower Species 

Supported in part by funding from New York Community Trust in 2024, and NCSWCD Part C Funding awarded in 2023 and 2025, the Preserve completed an ambitious effort to remove 0.6 acres of Phragmites as well as invasives in upland areas covering a total of 20,000 ft sq., such as Norway maple, Tree of heaven, and Japanese maple, and hydroseed with native grasses and flowers to help control invasive ground cover plants such as English ivy. 

Rain Gardens around Preserve Pond 

In Fall of 2016, two rain gardens, totaling 600 sq. ft., were constructed at the south parking lot to reduce runoff to the pond and adjacent Hempstead Harbor. A French drain was constructed along the entire downslope side of the parking lot to drain all of the stormwater from the parking lot into one rain garden, then the overflow from this garden goes into a stand pipe drain to the second rain garden through a pipe under the pathway that leads to the bridge. The rain gardens were funded by the National Fish and Wildlife Foundation, designed by nationally-recognized expert Rusty Schmidt, a Landscape Ecologist from Nelson, Pope & Voorhis and constructed thanks to Friends of Cedarmere, NCSWCD, Hempstead Harbor Protection Committee, and the Cornell Cooperative Extension Master Gardiners Program who all provided volunteers to work on the project.