A Texas Superstar, perennial Moy Grande Hibiscus, a rose mallow, “may be the largest flowered hibiscus on earth! Giant pink blossoms can be as large as dinner plates,” states the aggie-horticulture website. Blooms occur in flushes from summer until early fall. Moy grande tolerates alkaline soils making it an excellent flowering plant for areas of North Texas. Dr. Moy at the San Antonio Botanical Garden crossed Hibiscus moscheutos hybrid with Hibiscus grandiflorus to create Moy Grande.