Gardeners who live in coastal regions not only have to deal with the dry soil and high winds that often accompany life near the ocean, they also have to combat the detrimental effects of salt spray. Seaside garden plants must have a measure of salt-tolerance in order to thrive. When waves crash on the shore, they release a salty spray. Sea breezes carry the saline inland, where it accumulates in the soil and on plant foliage. For a thriving coastal garden, choose salt-tolerant plants.
Deciduous plants lose their leaves in cooler months. Shrubs that tolerate salty conditions include rugosa rose (Rosa rugosa). This deciduous shrub grows up to 5 feet tall with a 6-foot spread and prefers full sun and well-drained soil. Rugosa roses produce fragrant pink blossoms. The flowering quince (Chaenomeles speciosa) tolerates salty conditions. This flowering shrub produces red spring blooms and grows up to 10 feet tall with a similar spread. Plant in sun to light shade and well-drained soil. Other salt-tolerant choices include butterly bush (Buddleia davidii), clethra (Clethra alnifolia), rose of Sharon (Hibiscus syriacus) and bigleaf hydrangea (Hydrangea macrophylla).
The willow oak (Quercus phellos) grows from 80 to 100 feet tall with a 50-foot spread. This hardy deciduous tree thrives in full sun and well-drained soil.
The mahogany (Swietenia mahogany) grows up to 40 feet tall with a similar spread. This wide-canopied tree is prized for its attractive wood. Mahogany thrives in full sun to partial shade and grows best in moist soil. Other salt-tolerant choices include crape myrtle (Lagerstroemia spp.), thornless honeylocust (Gleditsia triacanthos) and trident maple (Acer buergerianum).
Evergreen plants keep all or most of their foliage throughout the winter. Salt-tolerant shrubs include the four-wing saltbush (Atriplex canescens). This hardy shrub also tolerates drought. Four-wing saltbushes grow from 3 to 15 feet tall with an equal to larger spread, depending on site conditions. Plant in full sun and dry soil.
Oleander (Nerium oleander) is also drought- and salt-tolerant. Oleander grows between 10 and 20 feet tall with a spread up to 8 feet. This toxic plant produces showy, fragrant flowers that range from white to red. Plant in full sun. Other salt-tolerant choices include Adam's needle (Yucca smalliana), century plant (Agave Americana), pittosporum (Pittosporum tobira) and yaupon holly (Ilex vomitoria).
The sand live oak (Quercus geminate) is drought- and salt-tolerant. This hardy tree grows up to 30 feet tall with a spread of 40 feet. Sand live oaks prefer full sun and dry soil.
The Southern magnolia (Magnolia grandiflora) grows up to 80 feet tall with a 50-foot spread. This ornamental evergreen prefers sun to partial shade and well-drained soil. Southern magnolias produce showy white blooms. Other salt-tolerant choices include black olive (Bucida buceras), Eastern red cedar (Juniperus virginiana) and Japanese black pine (Pinus thunbergii).