Outsidepride Ricinus Communis Castor Bean Zanzibariensis Seeds - 100 Seeds Castor bean zanzibariensis plants are an annual green foliage plant which can grow up to 96 inches tall in USDA Zones 3 - 11. Ricinus communis, or Castor Bean, known more as Castor oil plant, is a tropical annual that makes quite a stunning presence in the flower garden. This variety, Zanzibariensis, produces large, green leaves making a very head-turning display. This tall annual is often used to make a back-drop for other lower-growing plants in the summer garden Sow 1 - 2 of these heirloom, non gmo seeds per plant to begin growing this foliage plant.