15 -- Costal Gardening in the New York Region

The landscapes and gardens on or near our coast are challenged by harsh environmental conditions. The Atlantic coast of the New York metropolitan area is known as the Coastal Plain. Ranging from sandy beaches with and without dunes, to saltwater bays, to tidal salt marshes and their upland marshes, are numerous habitats. It is in these environments that high winds, temperature extremes, storm flooding, salt-spray, glaring sun and poor, salty soils wreak havoc on native ecosystems and ornamental plantings alike.

Dunes and backdunes are the most fragile ecosystems of all, subject to severe environmental conditions. They need to be left undisturbed. Beach grass, Ammophila brevilgulata, sea rocket, Cakile edentula,  beach pinwheel, Lechea maritima, and seaside goldenrod, Solidago sempervirens work simultaneously to stabilize the ever-shifting sand. On back dunes, hair grass, Deschamsia flexuosa, Eastern red cedar, Juniperus virginiana, Northern bayberry, Myrica pensylvanica switch grass, Panicum virgatum, pitch pine, Pinus rigida and beach plum, Prunus maritima help to establish and maintain this community. Both the low salt marsh and the high salt marsh are dominated by Spartina with salt marsh cordgrass, Spartina alterniflora, found growing where high tides flood twice daily, and salt hay or salt-meadow grass,  Spartina patens growing where flooding occurs only at very high tides. Native plants of the salt marshes include groundsel bush, Baccharis halimifolia, spike grass, Distichlis spicata, marsh-elder, Iva frutescens, and sea lavender Limonium carolinianum.

The coastal gardener’s challenge is salt damage. Plants are vulnerable in several ways: through root absorption and salt spray on the foliage. As salt-sensitive root hairs absorb water from soil, eventually excess salts destroy their cells. While salt accumulations challenge roots, salt spray damages foliage, producing symptoms of scorching or burning. Dune plants are the most salt-tolerant and as we garden beyond 1/8 mile from the sea, salt-tolerance becomes far less of an issue.

Here are design solutions and maintenance techniques which create a more successful growing environment, and which will also prevent the spread of invasive alien species.

• Avoid disturbance of natural areas, especially dunes and native vegetation which are critical to protecting both the natural and constructed coastal environment.

• Encourage and maintain naturally occurring buffer zones and stabilize with sand-binding natives as warranted.

• Plant salt-tolerant natives and non-invasive ornamentals wherever possible as they are adapted to the climate and soils and have co-evolved with pollinators, wildlife and fungus.

• Establish windbreaks with walls, fences and hedge plantings and under plant hedges with deciduous shrubs and forbs.

• Choose plants with tough, waxy leaves, and grey and woolly foliage.

• Utilize late flowering species, as spring arrives later and autumn lasts longer.

• Manage any invasive exotics to prevent flowering and seed dispersal.

• Rinse plants occasionally during the growing season to remove salt residue and avoid the possibility of scorching.

• Apply two-four inches of organic mulch to reduce temperatures and conserve soil moisture.

• Improve sandy garden soils by incorporating organic matter.

Invasive exotics tend to crowd out natives, disturbing and decreasing biodiversity. As gardeners, our role in responsible stewardship of these changing coastal areas will help to restore balance.

Windbreak Plants

Chamaecyparis obtusa–Hinoki falsecypress
*Juniperus virginiana–Eastern red cedar
*Myrica pensylvanica–bayberry
Pinus mugo–mugo pine
*P. rigida–pitch pine
*Prunus maritima–beach plum
*Rosa virginiana–Virginia rose

Woody ornamentals- Trees and Shurbs

*Amelanchier arborea–shadbush
*Aronia arbutifolia–red chokeberry
Buddleia Davidii–butterfly bush
*Ceonaothus americanus–New Jersey tea
*Clethra alnifolia–summersweet
*Cornus racemosa–red-panicled dogwood
*C. stolonifera–red-osier dogwood
*Ilex glabra–inkberry holly
*I. opaca–American holly
*I. verticillata–winterberry holly
*Juniperus virginiana–Eastern red cedar
*Myrica pensylvanica–Northern bayberry
*Pinus strobus–Eastern white pine
*Prunus maritima–beach plum
*Rhus copallina–shining sumac
*R. glabra–winged sumac
*R. typhina–staghorn sumac
*Rosa carolina–pasture rose
*R. virginiana–Virginia rose
*Vaccinium corymbosum–high bush blueberry
*Viburnum cassinoides–withered
Vitex agnus-castus–chaste tree

Ornamental Grasses and Groundcovers

*Arctostaphylos uva-ursi–Bearberry
Calamagrostis x acutiflora ‘Karl Foerster’–feather reed grass
*Distichlis x spicata–salt grass
Festuca glauca ‘Elijah Blue’–blue fescue ‘Elijah Blue’
*Juncus gerardii–black grass
*Juniperus conferta–shore juniper
*J. horizontalis–creeping juniper
*Panicum virgatum–broom sedge
Pennisetum alopecuroides–fountain grass
*Scirpus spicata–salt grass

Perennials

Achillea filipendula–yarrow
*Asclepias incarnata–swamp milkweed
*A. tuberosae–butterfly weed
*Aster tenuifolius–salt-marsh aster
Calendula officinalis–pot marigold
Coreopsis spp.–coreopsis
Echinacea purpurea–purple coneflower
Gaillardia spp.–blanket flower
Hemerocallis spp.–daylily
*Heuchera micrantha–hybrid coral bells
*Hibiscus mosheutos–rose mallow
*Limonium carolinianum–sea lavender
*Opuntia humifusa–prickly pear cactus
Nipponanthemum nipponicum–Montauk daisy
Sedum spectabile–stonecrop
*Solidago elliottii–swamp goldenrod
*S. sempervirens–seaside goldenrod
Stachys byzantina–lamb’s ears


*Denotes native to the New York region