Landscaping in Coastal Areas

by | Jun 15, 2017 | Butterflies, Garden Design, Groundcover, Native plants, wildflowers

Salt shear and onshore breezes often cause coastal maritime forests to grow at a slant away from the coast. Credit: Florida Master Naturalist Program

People from other parts of the country often move into Florida with expectations of their landscape beyond its capabilities. Those gorgeous peonies that grew up north or the perfect tomatoes they grew in California seem to wither in the heat or succumb to any number of insect or fungal pests. Adapting to our conditions takes listening to those with more experience, changing old habits or varieties and definitely adjusting expectations. Once you understand what the north Florida climate requires, you might be pleasantly surprised with a bumper crop of lemons or a thriving hibiscus that would never have worked in Michigan.

The same idea applies to landscaping on the beach or near areas of saltwater. Particularly on barrier islands like Perdido Key, Santa Rosa Island, and the coastal islands around Apalachicola, the influence of salt spray and hot, dry, sandy soils cannot be underestimated. If you have ever looked closely at the shape of the mature oak trees on the back sides of sand dunes, you’ll notice they’re shorter and tend to lean and grow away from the beach. This is due partially to the onshore breeze that steadily blows off the water, but also due to a phenomenon called salt shear. Salt shear occurs in areas where breaking waves release salt, which evaporates from water droplets and blows into the landscape. Unless specifically adapted to living in a saline environment, the salt can halt growth of the plants receiving the bulk of the spray. Many plants adapt to this by sealing up any vulnerable growing tips and sending energy for growth to the other side, resulting in a sloped shape. Land further inland from the Gulf will have consecutively less salt spray to endure.

Keep in mind that the soil on a barrier island is highly porous; it does not hold water nor nutrients well. The best option is to look at what grows there naturally, and select some of the most attractive and hardy choices for a home or commercial landscape. Knowing that a residence or commercial business is located within these environmental conditions, the best way to ensure success is to work with your surroundings instead of against them.

  • Muhly grass is a hardy landscape choice with dramatic fall blooms. Photo credit: Carrie Stevenson, UF IFAS Extension

  • Blanketflower reseeds annually and provides beautful color. Photo credit: Carrie Stevenson, UF IFAS Extension

  • Sand cordgrass is drought and salt tolerant and makes an excellent foundation plant in a coastal landscape. Photo credit: Carrie Stevenson, UF IFAS Extension

  • Sunshine mimosa runs along the ground and produces pinkish-purple flowers that are very attractive to bees. Photo credit: Carrie Stevenson, UF IFAS Extension

  • Beach sunflower forms mounds with bright yellow blooms. Photo credit: Sharyn Moore, Florida Master Naturalist

Below are a handful salt-tolerant options to consider.

Beach sunflower (Helianthus debilis): The yellow-blooming beach or dune sunflower will reseed and spread along as a hardy groundcover.

Muhly grass (Muhlenbergia capillaris): Muhly grass is a native clumping grass commonly used in Florida landscapes. It has showy pinkish-purple blooms in mid-fall.

Beach cordgrass (Spartina patens): Beach cordgrass is a native grass that serves as a sand stabilizer. While not particularly showy, it can serve as a good foundation plant.

Saw palmetto (Serenoa repens): These evergreen shrubs are extraordinarily hearty and long-lived. They produce a fruit that is an important food source for wildlife.

False rosemary (Conradina canescens): This evergreen shrub blooms purple, attracts wildlife, and is a hardy native species.

Firebush (Hamelia patens): Firebush has long-lasting red blooms that attract hummingbirds and native butterflies.

Blanketflower (Gaillardia pulchella): These colorful wildflowers attract pollinators like bees and butterflies and are extremely drought and salt tolerant.

Sunshine mimosa (Mimosa strigillosa): This ground-running plant has colorful, spherical pink blooms and attracts bees. The delicate leaves of the plant are sensitive to touch, and will fold up when touched.

 

For more information on salt-tolerant coastal plants and trees in our area along with cold-tolerant palms, contact your local Extension agent or Native Plant Society.

Carrie Stevenson
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