Native Plants for Southern Connecticut Rain Gardens and Wetlands

In Southern Connecticut, the breath-taking summer color is in the riparian buffer zones. Here, plants crowd each other for water and sun, creating a cheerful, lively mix that supports pollinators, amphibians, water fowl, and a whole host of other creatures.  Further, the riparian buffers protect the waterways by filtering out pollutants before they get in the water; the buffer zones also protect the banks of our streams, lakes and ponds from erosion.

If you are lucky enough to have property abutting a stream, pond, or river, you can have the most delightful native plants and companion wildlife.  Don’t live by water?  Then, make a rain garden.  Just about any home gardener can create a rain garden that helps the environment by diverting run-off that would otherwise end up in the storm sewers.

painted turtles and arrow arum in the Bartlett Arboretum wetlands

So what to plant?

Native Medium to Large Trees for Wetlands

First, the big trees. In New England, the trees are supposed to lean out over the water, creating cool summer shade that keeps water temperatures suitable for the water plants and creatures.  Further, the very tall ones, like the sycamore and the tulip tree are excellent raptor habitat.  Design note: the tall trees’ wonderful autumn colors will be reflected in the water.  The following medium-to- large trees all thrive along our water waterways (see Native Trees for Southern New England for descriptions):

• Red maple, swamp maple (Acer rubrum)
• Silver maple (Acer saccharinum)
• White Ash (Fraxinus Americana)
• Green Ash, Red Ash (Fraxinus pennsylvanica)
• Tulip tree, tulip poplar, yellow poplar (Liriodendron tulipifer)
• Sour gum, black gum, tupelo (Nyssa sylvatica)
• American Sycamore (Platanus occidentalis)
• Black cherry (Prunus serotina)
• Swamp White Oak (Quercus bicolor)
• Eastern cottonwood (Populus deltoides)
• Black willow (Salix nigra)
• Red elm, rough elm, slippery elm (Ulmus rubra)

Chipmunk at Scalzi Riverwalk Nature Preserve having lunch in a black willow.

Native Small Trees and Shrubs for Wetlands

The smaller trees and shrubs are the “bones” of all gardens. In the riparian buffer, the choices are seemingly endless (see Native Shrubs for Southern New England  for descriptions):

• Speckled alder (Alnus rugosa)
• Shadblow, shad, serviceberry (Amelanchier canadensis, etc.)
• Hornbeam, ironwood (Carpinus caroliniana)
• Buttonbush (Cephalanthus occidentalis)
• Sweet pepperbush (Clethra alnifolia)
• Silky dogwood (Cornus amomum)
• American hazelnut, American filbert (Corylus americana)
• American witchhazel (Hamamelis virginiana)
• Winterberry (Ilex verticillata)
• Swamp honeysuckle (Rhododendron viscosum)
• Elderberry (Sambucus canadensis)
• White Meadowsweet (Spiraea alba)
• Swamp rose (Rosa palustris)
• Pussy willow (Salix discolor)
• Bebb’s willow (Salix bebbiana )
• Blueberry (Vaccinium angustifolium, V. corymbosum)
• Arrowwood viburnum (Viburnum dentatum)

Swallowtail drawn to the Clethra, Bartlett Arboretum wetlands

Native Vines for Wetlands

Twining vines add even more color and wildlife food.  All of the ones on this list tend to be fairly well behaved except climbing boneset.  I list climbing boneset, even though it can get out of hand, because it attracts the most amazing pollinators and is great fast cover if you need it.

• Virginia creeper, woodbine (Parthenocissus quinquefolia), (P. inserta)
• Wild Yam (Dioscorea villosa)
• Groundnut (Apios Americana)
• Hog Peanut (Amphicarpaea bracteata) (pictured below)
• Climbing Boneset, Hempweed (Mikania scandens) (pictured below)
• Fox Grape (Vitis labrusca)
• Riverbank Grape (Vitis riparia)
• Bur Cucumber (Sicyos angulatus) (annual)

Eastern Joe Pye-weed is lovely even when not in flower, Scalzi Riverwalk Nature Preserve

Native Wildflowers, Ferns and Grasses for Wetlands

Many wonderful wildflowers find their special niche tucked under and around the above trees and shrubs.  There are too many to name here, so I’ve including only some of  the most popular that might be easiest to find in a local native plant nursery.  In fact, this list comes directly from the Earth Tones Nursery catalog , where you can get descriptions.

• Swamp Milkweed (Asclepias ncarnata) (pictured below)
• Marsh Marigold (Calthra palustris) (pictured below)
• White Turtlehead (Chelone glabra)
• Joe Pye Weed (Eupatorium fistulosum) (pictured below)
• White Snakeroot (Eupatorium rugosum)
• Allegheny Monkey Flower (Mimulus ringens)
• Cardinal Flower (Lobelia cardinalis)
• Blue Flag Iris (Iris versicolor)
• White Meadow Rue (Thalictrum pubescens)
• Sensitive Fern (Onoclea sensibilis) (pictured below)
• Royal Fern (Osmunda regalis)
• Common Cattail (Typha latifolia)

Green heron with native rushes and sedges, Cove Island Wildlife Sanctuary

Additional notes:

– Several violets, asters, wild sunflowers, and goldenrods will do well in damp areas, see the CT Botanical  list below.

– For grasses, most local sedges are good as is bur-reed (Sparganium arnericanum).

– I adore the yellow Fringed Loosestrife (Lysimachia ciliata)  which loves a sunny, wet meadow.

– If you like a tropical look, try the giant Cow Parsnip (Heracleum maximum).

– Skunk cabbage is an amazing plant but not to everyone’s taste (for some strange reason).

– Right at the water’s edge, go for the showy-leafed Arrowhead (Sagittaria latifola), Pickerelweed (Pontederia cordata) Arrow-arum (Peltandra virginica), and Water-plantain (Alisma subcordatum).

Design Considerations

– Cluster plants like you would in in garden - several shrubs together, a wide shorter space for forbes, etc.

– Do not evenly space plants of similar heights- it looks totally unnatural.

– Plant in masses – best to have several of each plant.

– Plant right up to the water’s edge where the plants’ crowns will be under water in floods.

– Leave some paths and trails for water access for you and for the ducklings, turtles, etc.

– ”Wetlands” doesn’t so much mean “near the water” as “near the water table”.

– Wetland plants want their roots extending down into or near the water table most of the year.

– A steep slope or a badly undercut river bank may be near water but far above the water table and not suitable for wetland plants.

– Make sure some of the shrubs will over hang the water as they grow.

– Tuck the grasses, ferns, etc. in the base of the taller plants.

Fish enjoy the shade under a silk dogwood, Scalzi Riverwalk Nature Preserve

The other  posts in this series are: Native Shrubs and Small Trees for Southern New England, Native Trees for Southern New England, Southern New England’s Native Vines,  and Nature’s New England Winter Garden Design.

Further reading:
Connecticut Botanical Society  has a list of local native plants that do well in moist conditions.
Inland Wetlands Plants of Connecticut  Here’s good list created in the BTD (Before the Deer) era.  This list  is so old that it lists the native Phragmites – long gone to its invasive Asian kin.Field Guide Connecticut’s Invasive Aquatic and Wetland Plants  -it’s good to know what you don’t want!A Wetlands Primer  from The Stamford Land Conservation Trust
New England Wetland Plants Inc.-tends to be geared toward larger orders but has lots of interesting information on its web site.

UConn’s  Brochure on Rain Gardens – useful  background on rain garden construction but the  planting list is from the entire eastern seaboard – it’s so much better for the environment and the wildlife, I think,  to stick to local Connecticut native plants.

Young frog hiding under tussock sedge and meadow rue, Bartlett Arboretum

Climbing boneset, Bartlett Arboretum wetlands

Sensitive fern, Scalzi Riverwalk Nature Preserve

wild sunflower (helianthus), Scalzi Riverwalk Nature Preserve

Fringed Loosestrife at Scalzi Riverwalk Nature Preseve

Blue skullcap, rare but wonderful, Scalzi Riverwalk Nature Preserve

Spring beauty, wonderful spring ephemeral for sunny wetland banks, Scalzi Riverwalk Nature Preserve

The lovely, versatile hog peanut vine, Scalzi Riverwalk Nature Preserve

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