The Effect of Salt Spray on Coastal Plants

Airborne Salt Basics

• Salt appears naturally in all soil. Plants need it only in small amounts. In coastal areas, tiny droplets of salt water enter the air when waves break on the shore. Sea breezes blow the salty air toward land. The amount of salt that comes into contact with plants and soil depends on the proximity of a garden to the beachfront. Maritime forests can provide an effective barrier to salt spray. However, in some areas the protective forests are now gone, due to development exposing plants to salt spray damage.

Effects

• Salt spray affects plants in a myriad of ways. If you are trying to start a garden, athe salt can retard seed germination. As plants begin to develop, the salt also inhibits growth. Gardens of edible crops have reduced yields due to the salinity of soil from the salt spray. The plant’s ability to absorb moisture also declines. The signs of salt spray-damaged plants includes wilting and dieback.

Management

• Non-salt-tolerant plants eventually die from prolonged exposure to salt spray. Regular overhead irrigation can wash the salt off plant foliage and reduces the negative effects of salt spray. Gardeners can add fresh water to the soil to dilute the salt that accumulates in soil. Building barriers such as fences to block the salt spray can help less salt-tolerant plants grow. When a home is near the sea, the lawn has two microclimates. Gardeners should plant salt-tolerant plants on the side of the house that faces the water. The other microclimate is the side of the house that faces land. Plants on this side of the house have a barrier to the salt spray and protection from ocean winds.

Salt-Tolerant Plants

• Living in a coastal area does not mean you cannot have a thriving, colorful garden. You can choose plants that survive salt spray and provide attractive vegetation, from small trees to ornamentals. Trees that withstand high amounts of salt include devilwood (Osmanthus americanus), redbay (Persea borbonia) and sand live oak (Quercus geminata). Devilwood grows in U.S. Department of Agriculture hardiness zones 5B through 9B. Redbay grows in USDA zones 7B to 11. Sand live oak grows in USDA zones 7 to 10. A vegetable that has a high tolerance to salt is asparagus. It grows in USDA zones 4 to 9. Flowers that have a moderate tolerance for salt include chrysanthemums, a large genus of flowers that bloom in a variety of showy colors. The hardy garden mum (Chrysanthemum morifolium) is a popular species that grows in USDA zones 5 to 9.