The castor bean plant's colorful foliage can make it a conversation-starting addition to your backyard. Its ability to reach 20 feet in height or more also makes it a potential privacy screen or windbreak. You can grow castor bean plants if you live in USDA hardiness zones 8a through 11. Though the plants can sometimes be sourced from a nursery, you can easily start the plant by sowing the actual castor bean seed.
Prepare the castor bean seeds. Place the seeds in a dish and fill the dish with water. Soak the seeds for 24 hours.
Ready the ground for planting while you're waiting for the seeds to finish soaking. Choose an area of your yard that receives direct sunlight for seven or more hours. Remove all surface vegetation and debris and break up the soil to a depth of 8 to 12 inches.
Amend the soil. Add 1 to 2 inches of compost and thoroughly mix it into the soil. This boosts the soil's nutrient levels and also increases its organic content, which helps with moisture retention.
Sow the castor bean seeds. Sink each seed an inch below the surface of the soil. If you're planting more than one castor bean seed, separate the seeds by 24 inches.
Water the seeds twice daily to keep the soil moist. They will typically germinate within 14 days. Continue watering twice daily, as the plants thrive on lots of water.
Add an inch of mulch around the base of the castor bean plant once it reaches a height of 3 to 5 inches. Mulch helps to conserve soil moisture.