Gardenwise: Make Your Coastal Garden Storm-Ready
Pictured Above: Eastern baccharis grows in wetland environments, which makes it ideal for coastal gardens. Its flowers take on the appearance of cotton balls over time | Mina Vescera photo
by Susan Tito
Long Islanders lucky enough to live near the ocean, a bay or Long Island Sound know that their good fortune could change at a moment’s notice in the face of a catastrophic storm. Many homeowners who worry about how their dwellings will hold up during extreme weather also stress out over their gardens.
Nor’easters and hurricanes, which occur more frequently this time of year, are the bane of every coastal gardener because they pack a powerful one-two punch with their brutal winds and damaging salt deposits.
“Gardening near the shore means that your plants need to be tolerant of drying winds, which can cause leaves to lose water faster than roots can supply,” said Mina Vescera, nursery/landscape specialist at Cornell Cooperative Extension in Riverhead. “And wind carrying aerial salts demands another level of defense from plants.”
That’s because salt is a corrosive drying agent, especially when deposited on a plant that doesn’t tolerate it. “Plants with salt injury have similar symptoms to those that are drought-stressed — their leaves appear scorched,” said Ms. Vescera.
Wind carrying aerial salts demands another level of defense from plants.— Mina Vescera, CCE
Salt can wreak havoc in another way. In low-lying areas prone to flooding, saltwater disrupts a plant’s ability to take up water, which inhibits growth. Specifically, the plant must expend more energy to absorb the water. At the same time, salt draws water out of the plant, resulting in dehydration followed by death.
The physiology of salt-tolerant plants is a little different: The leaves of all plants have an outer layer called the cuticle, a waxy coating that varies in thickness depending on the species, but plants that thrive in a coastal environment have thicker cuticles.
“Plants adapted to windy conditions tend to have smaller leaves that are thicker, like needled evergreens, or have many fine hairs that disrupt wind flow like catmint,” said Ms. Vescera. “And plants with thin, large leaves that do not have a pronounced waxy cuticle may not be tolerant of aerial salts.”
When planning your coastal garden, see what kind of plants flourish in your area, either in the wild or in a neighbor’s yard. For example, it seems like everybody on the East End has rose of Sharon (Hibiscus syriacus) or privet (Ligustrum) species. That’s because these plants fare well in terms of wind and salt spray tolerance and have a tendency to spread.
If you don’t want a garden-variety garden, do your research. You may be surprised at the range of hardy and salt-tolerant plants available for your landscape.
Grasses are great to include in a coastal garden. Indian grass (Sorghastrum nutans) is a warm-season native with silvery blue foliage and sand-colored inflorescences. Fountain grass (Pennisetum alopecuroides), another warm-season grass, has showy bottle bush-like flower spikes.
If you are looking for a tough woody shrub, choose Eastern baccharis (Baccharis halimifolia), also known as saltbush, a late-summer blooming deciduous native that has flowers resembling cotton balls. Beach plum (Prunus maritima) and summersweet (Clethra alnifolia) are also good native choices. Spotted laurel (Aucuba japonica), which is a well-behaved non-native evergreen, is moderately salt tolerant. Its glossy dark green leaves are striking in shaded areas.
There are a number of trees native to eastern North America worth considering for a coastal garden. Three of my favorites are serviceberry, eastern red cedar and pitch pine.
Serviceberry (Amelanchier canadensis) has great ornamental value: Showy white flowers in early spring give way to edible summer berries followed by orange-red leaves in fall. Eastern red cedar (Juniperus virginiana) and pitch pine (Pinus rigida) are tough evergreens that often grow where other species cannot thrive.
Many perennials perform well in coastal conditions, among them, baby’s breath (Gypsophila), bee balm (Monarda), catmint (Nepeta), foxglove (Digitalis), lily of the valley (Convallaria), peony (Paeonia) and Phlox, to name a few.
For a more comprehensive list, visit the Long Island Horticulture Resource Guide, produced by the Cornell Cooperative Extension of Suffolk County. Scroll down to page 59 for the list of salt-tolerant plants.
When it comes to salt tolerance, the big takeaway is that there is variability among species. Some conditions are just too extreme.
“During Hurricane Sandy, even moderately salt-tolerant plants such as eastern red cedar and sweetgum were damaged because of the excessive salt deposition that occurred during the storm,” said Ms. Vescera.
A lot depends on the conditions of your site and specific plants, so choose wisely. After all, a hardy plant worth its salt will go a long way to making your coastal garden beautiful — and ready for the next big storm.
Susan Tito is a freelance writer and proprietor of Summerland Garden Design & Consulting (summerlandgardendesign.com). She earned a certificate in ornamental garden design from the New York Botanical Garden and is a member of the American Horticultural Society and Garden Communicators International. She can be reached at firstname.lastname@example.org.