Grass Island Management Conservation Area
off of Shore Road, Greenwich, Fairfield County, Connecticut


I-95 north to exit 3; turn left onto Arch Street; turn left onto Horseneck Lane; turn left on Shore Road; turn left onto Grass Island Road.


1712 – John Howe purchased Grass Island. (Howe gave the Greenwich Harbor island it’s name.

1898 – the Connecticut General Assembly granted Daniel S. Mead the right to construct sea walls in front of and around the island. The purpose of the walls was to improve the quality of the land.

Before 1909 – Grass Island was really a true island.

1909 – Grass Island grew to nearly twice it’s original size from a series of fill.

1916 – the land was advertised for sale as property suitable for construction.

The town bought the property from Oliver Mead for use as a sewage disposal plant. A causeway was built from the mainland to Grass Island.

During the Prohibition Era – the island was used as a dumping ground where police men would break up confiscated liquor bottles.

1937-1940 – the island doubled in size.

1945 – the southern causeway closed.

1945 – the northern causeway expanded.

1950’s – Grass Island ceased as a true island. Fill from construction of the Connecticut Turnpike was placed beside the former causeway.

1960 – a new sewage treatment plant built

1975  --  creation of a managed conservation area following an environmental study sponsored by the Conservation Commission.


boat house, boat yard and dock area, small preserve at the southern tip of the Island, nature trail, a 14 acre managed conservation area, a public marina, the Greenwich Boat and Yacht Club and the Town’s wastewater treatment plant, picnic table

Roger Sherman Baldwin Park can be seen across the Harbor to the southwest. 


wooded areas, meadows, and one of the few remaining salt marshes in Town


squirrels, cottontail rabbits and other small mammals along with a host of birds (Wintering Great Horned Owls and Long Eared Owls, Ring-necked Pheasants, Mallards, Black Ducks, Wigeons, Gadwalls, Canada Geese, Herons, Egrets and Terns)


Town of Greenwich Department of Parks & Recreation, Grass Island.


10/22/2005.  On a rainy day, Rosemary Cooney, Sarah-David Rosenbaum, Ceferino Santana, dog Sonar and I hiked around the managed area.  We decided to tour the park by heading counter-clockwise following a huge red mark on a tree thinking that was the start of the trail.  It was only after we had tramped around for awhile, we finally discovered the trail.

The place to start the trail is on the southern edge of the place.  The trail here is marked by a hedge of trees.  The trail heads clockwise on the southern end following parallel with the waste treatment facility (surrounded by a wire fence).  There is post #2 here along with numerous yellow arrows on brown plaques pointing the way.  The trail opens up into an open lawn area with scattered trees.  Following the arrows the trail heads west to an asphalt trail that goes all the way to Shore Road.  Along the way it parallels the salt marsh bordering Greenwich Harbor.  The trail itself does not go all the way to Shore Road; rather at post #4 it  heads to the right (north) off the asphalt path down to a Phragmites marsh surrounded by lots of pin oaks. Here is post #5.  After that I do not know which way the trail goes since we had traveled counter clockwise rather than clockwise.  Of course, it is easy enough to work your way back to the parking area thereby making a loop trail out of the path.   Dr. Patrick L. Cooney. 

Dr. Patrick Cooney, Sarah-David Rosenbaum, Rosemary Cooney

*  = plant blooming on date of field trip, 10/22/2005

Acer negundo (ash-leaf maple)
Acer platanoides (Norway maple)
Acer rubrum (red maple)
Acer saccharinum (silver maple)
Acer saccharum (sugar maple)
Ailanthus altissima (tree-of-heaven)
Betula populifolia (gray birch)
Carya cordiformis (bitternut hickory)
Fraxinus americana (white ash)
Juniperus virginiana (red cedar)
Liquidambar styraciflua (sweetgum)
Morus alba (white mulberry)
Picea abies (Norway spruce)
Pinus strobus (white pine)
Pinus sylvestris (Scots pine)
Pinus thunbergii (Japanese black pine)
Platanus sp. (sycamore)
Prunus serotina (black cherry)
Pyrus malus (apple)
Pyrus sp. (crab apple)
Quercus alba (white oak)
Quercus palustris (pin oak)
Robinia pseudoacacia (black locust)
Ulmus americana (American elm)

Amorpha fruticosa (false indigo)
Berberis thunbergii (Japanese barberry)
Elaeagnus umbellata (autumn olive)
Cornus amomum (swamp dogwood)
Elaeagnus umbellata (autumn olive)
Iva frutescens (marsh elder)
Lonicera morrowii (Morrow's honeysuckle)
Rhus glabra (smooth sumac)
Rosa multiflora (multiflora rose)
Rosa rugosa (wrinkled rose)
Rosa sp. (horticultural rose)     *   planted
Rubus phoenicolasius (wineberry)
Rubus sp. (blackberry)

Ampelopsis brevipedunculata (porcelainberry)
Calystegia sepium (hedge bindweed)
Celastrus orbiculatus (Asiatic bittersweet)
Hedera helix (English ivy)
Lonicera japonica (Japanese honeysuckle)
Parthenocissus quinquefolia (Virginia creeper)
Toxicodendron radicans (poison ivy)

Acalypha sp. (three-seeded mercury)
Achillea millefolium (common yarrow)
Aegopodium podagraria (goutweed)
Alliaria petiolata (garlic mustard)
Ambrosia trifida (giant ragweed)
Apocynum sp. (dogbane)
Arctium minus (common burdock)
Artemisia vulgaris (common mugwort)
Asclepias syriaca (common milkweed)
Aster spp. (aster)     *
Cichorium intybus (chicory)     * 1 flower in bloom
Daucus carota (Queen Anne's lace)
Helianthus sp. (tuberous)?  (Jerusalem artichoke)
Hemerocallis fulva (tawny day lily)
Impatiens capensis (orange jewelweed)     *
Linaria vulgaris (butter and eggs)     *
Limonium carolinianum (sea lavender)
Phytolacca americana (pokeweed)
Portulaca oleracea (common purslane)
Rumex sp. (dock)
Salicornia sp. (glasswort)
Silphium perfoliatum (cup plant)
Solanum dulcamara (bittersweet nightshade)
Solidago sempervirens (seaside goldenrod)     *
Trifolium pratense (red clover) 
Taraxacum officinale (common dandelion)     *

Cyperus sp. (flat sedge) like bipartitus

Dactylis glomerata (orchard grass)
Phragmites australis (giant reed grass)
Setaria glauca (yellow foxtail grass)
Spartina alterniflora (salt marsh cord grass)
Spartina patens (salt meadow cord grass)


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