Scientific Name: "rosa-sinensis". The Hibiscus plant grows about 6 feet tall, 6 feet wide and has medium-sized glossy green leaves with large flowers of a tropical appearance.Hibiscus are deciduous shrubs with dark green leaves; the plants can grow to 15 feet tall in frost-free areas. Flowers may be up to 6 inches diameter, with colors ranging from yellow to peach to red. Hibiscus can be planted singly or grown as a hedge plant. Select a site with full sun and well-drained soil. Hibiscus also adapt well to growing in containers. Plant in spring, summer, or fall, spacing plants 3 to 6 feet apart. Hibiscus require at least 1 inch of rain (or equivalent watering) each week. Hibiscus are sensitive to cold and should be protected when temperatures dip into the 30s.