Castor bean is a great way to turn your garden tropical on a budget. This easily grown seed annual will reach heights of up to 12 feet. The leaves are often 18 inches or more in diameter with 5-12 lobes. Colors range from green with white stripes to deep burgundy. Castor bean prefers full sun and will grow rapidly if given plenty of water. Fertilize once a month and mulch to keep soils moist. The spiny seed capsules produced after flowering are also quite dramatic. The seeds are extremely poisonous. Castor bean combines well with palms, bananas and canna for a jungly look.