The tropical hibiscus (Hibiscus rosa-sinensis) features evergreen foliage and large, showy flowers that bloom from summer through fall. Although the plant is hardy in U.S. Department of Agriculture plant hardiness zones 10 through 11, it's usually grown as a potted plant since it can't tolerate temperatures below 30 degrees Fahrenheit. Proper care and maintenance keeps a tropical hibiscus healthy and encourages abundant blooms in season.