Most plants grow better in freshwater than they do in saltwater. Exposure to sodium can cause plants to wither and die, especially if they are not used to saltwater environments.
Some trees, such as black walnut and sweetgum, can tolerate mild exposure to salinity. Certain plants can grow in soil with high saline content, while others can withstand salt spray, such as from rain drops laden with salt.
Most plants are most vulnerable to salinity during their infancy. They acquire better tolerance as they age.
Signs of salt damage on landscaping plants include discoloration of the leaves and stems, reduced fruit sizes and greater quantities of dropped leaves.