The common name, Rose of Sharon, often suggests a connection to roses, but this plant is entirely unrelated to the rose family. The use of this biblical name has led to confusion regarding its identity and relationship with other flowering shrubs. Many people wonder if the Rose of Sharon is a type of hibiscus because of its showy, mallow-like flowers. The answer directly resolves the uncertainty surrounding this popular garden plant.
The Botanical Relationship
The Rose of Sharon is a member of the broader hibiscus family, confirmed by its scientific name, Hibiscus syriacus. All plants sharing the first part of their scientific name belong to the same genus, a group of closely related species. Therefore, the Rose of Sharon is a specific species within the Hibiscus genus, making it a true hibiscus. The genus Hibiscus is quite large and includes many different species, such as the tropical hibiscus, Hibiscus rosa-sinensis. This tropical species is typically grown in warm climates or as a houseplant, contrasting with the cold-hardy Rose of Sharon.
Distinguishing Characteristics of Hardy Hibiscus
The reason the Rose of Sharon is often not recognized as a hibiscus stems from its distinct growth habit and hardiness. Unlike tropical species, which are evergreen shrubs surviving only in frost-free USDA Zones 9 to 11, the Rose of Sharon is a deciduous, woody shrub or small tree. It sheds its leaves in the fall and survives cold winter temperatures, thriving in temperate regions from USDA Zones 5 to 9. This cold tolerance separates the hardy types from their tropical cousins, which are killed by freezing temperatures.
The structure of the Rose of Sharon is distinct, forming a multi-stemmed, upright shrub that can reach heights of 8 to 12 feet. This contrasts with other hardy hibiscus species, such as Hibiscus moscheutos, which are herbaceous perennials that die back to the ground each winter and regrow from the roots in the spring. The Rose of Sharon blooms later than many garden plants, producing its 2-to-4-inch flowers from mid-summer until fall. Its flowers are smaller than the “dinner-plate” blooms of the herbaceous hardy hibiscus, but they are more numerous and cover the woody structure of the plant.
Essential Care for Rose of Sharon
The Rose of Sharon is valued for its low maintenance requirements and adaptability once established. For the best flowering performance, it should be planted in full sun, meaning at least six hours of direct sunlight each day. While it can tolerate partial shade, too little sun results in fewer blossoms and less vigorous growth. The plant is adaptable to various soil types, but the ground must be well-draining, as it does not tolerate standing water or overly wet roots.
During the first year after planting, regular deep watering is necessary to help the root system become established. Once mature, the Rose of Sharon exhibits good drought tolerance, though consistent moisture produces the most impressive flowering display. Pruning is typically done in the late winter or early spring before new growth appears, as the flowers are produced on the new wood grown in the current season. Pruning can be used to shape the plant, manage its size, or remove suckers growing from the base.