Marine areas with salt spray and exposure to tides and flooding tend to have salty soil. In other areas, fertilizers and manure combined with poor drainage cause the soil to be salty. Any poorly drained soil accumulates salt over time. Many annuals do not tolerate salty soil, but some species will tolerate a moderate amount of salinity. These species also prefer full sun and are generally drought tolerant.
Baby Sun Rose
The baby sun rose (Aptenia cordifolia) grows 3 to 4 inches high, has glossy dark green foliage and produces red flowers that bloom all year. The flowers are shaped like aster flowers. This plant is best used in hanging baskets, trailing down walls and as a ground cover, especially in rock gardens. Baby sun rose plants like full sun and well-drained soil. The soil should get dry between waterings. This plant has a high drought tolerance and is hardy in USDA zones 10 to 11.
The periwinkle vinca (Catharanthus roseus) has white, pink or purple flowers. This plant grows 1 to 2 feet high and wide and is used in hanging baskets, in borders, as edging or as a ground cover. This vinca likes very well-drained soil and needs very little watering. Too much water causes root rot and disease, and ends the flowering season. This plant is hardy in USDA zones 10 to 11 and can be planted any time of year there. In USDA zones 7 to 9, the vinca should only be planted in the warmer months.
Zinnias come in a variety of heights, according to the species, and range from 6 inches to 3 feet tall. Dwarf varieties are less than 10 inches tall, while intermediate varieties are around 15 inches tall. These plants do not like wet soil and have a very high drought tolerance. The zinnia needs to be deadheaded to keep producing flowers and is hardy in all USDA zones. Zinnias are fast growing and produce flowers in all colors except blue.
Gaillardia produces flowers in yellow, orange, red and mixtures of those colors. This plant attracts butterflies and is hardy in USDA zones 3 to 11. Like the other plants listed, Gaillardia prefers full sun and well-drained soil. This plant also has a high drought tolerance and grows to 12 to 24 inches tall.