Hibiscus coccineus, also known as scarlet hibiscus or scarlet rose mallow, can best be described as a shrub-like perennial plant that adds bold, red color to any landscape. Gardeners likely will find the scarlet hibiscus in warm-weather climates, where temperatures reach above 40° Fahrenheit (or approximately 4.5° Celsius). For the best results of full blooms, the ornamental shrub should be planted in bright light and wet conditions. Once the hibiscus flowers bloom, they may be used mostly in ornamental settings.
The crimson red scarlet hibiscus comes from a family of wildflower plants that are distinguished by their shapes, among other features. The Malvaceae, or mallow, family consists of plants that bloom alternating lobed or toothed leaves, as well as flowers that come with five petals of various colors. In addition to the hibiscus coccineus, approximately 1,500 species of herbs and shrubs comprise the Malvaceae family. Some examples of hibiscus relatives include hollyhock flowers, cotton, and okra.
Warm weather helps the hibiscus coccineus thrive. Considered to be a native North American plant, the hibiscus grows naturally in the swamps, rivers, and marshes of the southeastern United States, including Florida, Alabama, and Georgia. The hibiscus may be native to the United States, but it can grow anywhere with a warm, tropical climate in USDA hardiness zones 7 to 11. Temperatures must range from 0° Fahrenheit (approximately -15° Celsius) to 40° Fahrenheit (4.5° Celsius) or warmer for the hibiscus coccineus to thrive.
Gardeners must follow specific cultivation requirements for the scarlet hibiscus to grow successfully. Seeds or roots may be used to plant the perennial in moist soil conditions with some flooding. The hibiscus coccineus works well with acidic clay, sandy, or loamy soils, and may need additional watering during dry spells. The perennial hibiscus also fares well in bright, full sunlight with only slight shading.
Planting areas must also provide ample space for the scarlet rose mallow to grow upward as well as outward. The University of Florida Extension recommends spacing the plants no more than 36 inches (approximately 91 cm) apart, whether they bloom as tropical trees, bushes, or shrubs. By spring, the average scarlet hibiscus grows up to 8 feet (approximately 2.4 m) tall and spreads out to 4 feet (approximately 1.2 m) wide. The scarlet red flowers usually debut by the summer season. The leaves and flowers of the hibiscus tree die back by the winter season, only to reappear during the following spring.
The scarlet hibiscus serves several decorative purposes. Some gardeners may plant the perennial near ponds or streams to accent the landscape. Others may opt to plant the scarlet rose marrow as a border along flowerbeds, where it can attract hummingbirds and butterflies.