The Rose of Sharon (Hibiscus syriacus) is a species of hibiscus desirable for its large, summer-blooming flowers. The shrub grows upright rather than out, and can be trained on one trunk to form a tree-like shape. The Rose of Sharon can grow to 10 feet tall and wide, and is an excellent choice for home gardeners who want an easy-care specimen plant.
Hibiscus syriacus can be grown outdoors in USDA Hardiness Zones 5B through 9A, according to the University of Florida. In other climates, the Rose of Sharon can be grown in containers and moved indoors when the weather cools, but they perform best as outdoor plants.
Plant your Rose of Sharon where it will receive full sunlight. This shrub can tolerate hot temperatures, according to the University of Connecticut. Hibiscus syriacus can also grow in partial shade, but it will not bloom in full shade conditions.
Soil and Water
The Rose of Sharon is hardy in that it can tolerate any type of soil. For that reason, it is often planted in poor soil along roadways. Do not plant it where standing water develops, as too much water can cause the shallow roots to rot. On the other hand, although the Rose of Sharon is drought-tolerant, it blooms much better if the soil is kept continually moist.
The wood and bark of Hibiscus syriacus is soft and fragile. In windy areas, the branches may break easily, so plant it where it will be protected from strong winds. Garden tools can easily penetrate and damage the bark, causing open wounds where fungal disease can enter the tree, so take care when pruning. In fact, pruning isn't usually needed or recommended for these plants, according to the University of Florida.
Aphids often infest these shrubs, covering new growth and causing that growth to become misshapen or stunted. Aphids can be rinsed off with a strong stream of water, or killed with insecticidal sprays. Japanese beetles will also eat the flowers and should be plucked off smaller bushes if possible, since insecticidal sprays are usually ineffective against these major insect pests.