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How to Raise Castor Beans

By Kimberly Sharpe ; Updated September 21, 2017

The castor bean plant (Ricinus communis) is grown for its production of castor oil, animal feed and as an ornamental garden specimen. The plant is highly toxic and contains a chemical known as the protein ricin and the alkaloid ricinine. When the plant and beans are boiled, the toxins are removed. The seeds are then squeezed to remove the oil. The remaining hulls are used in animal feed. The plant is impressive in appearance and size. It will easily grow to 40 feet. Castor bean plants are grown year-round as evergreen herbaceous trees or shrubs in tropical climates, but in colder areas they are grown as annuals.

Soak castor beans in a bucket of water for 24 hours before planting. Nick the very end of each seed with a sharp razor blade, just enough to make a very tiny superficial cut in the seed's outer layer. Sow seeds indoors six weeks before the expected last frost if growing in cold regions of the country. Plant the seeds in a potting mix in a small starting container. Place the container in a sunny window for germination to begin.

Plant in a location that offers ample space for the fast-growing castor bean plant.

Plant castor bean plants in a sunny location that affords wind protection. Plant castor bean plants in groups for the best overall effect.

Place the seeds 1 inch deep in the soil. Mix the soil at a ratio of 50 percent peat moss with 50 percent garden soil and plant in well-drained soil.

Water the castor bean plant seeds regularly, enough to maintain a moist soil.

Cut the plants back after a hard freeze. Dispose of the plants' remains in a plastic bag.

Support the castor bean plants using garden stakes with cotton rope if the plants become so large they begin to fall over. Castor bean plants are extremely susceptible to wind damage.


Things You Will Need

  • Razor blade
  • Bucket
  • Peat moss
  • Garden stakes
  • Cotton rope
  • Planting containers
  • Potting soil
  • Plastic bags
  • Pruning shears


  • Castor bean plants can easily grow 40 feet tall in a tropical region. In northern regions, plants can grow to 12 feet tall under ideal circumstances, but often only grow to 3 feet tall before a hard freeze kills the plant.
  • Castor bean plants enjoy growing alongside ponds, streams or other bodies of water, but they do not take well to having waterlogged roots for an extended amount of time.
  • Castor bean plant seeds enjoy a moist soil environment to germinate. The plants do best when they receive 7 to 11 inches of rain annually once fully grown. In tropical regions this often can be achieved through annual rainfall. In dryer climates the castor bean plants will require watering regularly to maintain their needs.
  • The castor bean often can come back on the remaining roots the following spring if the winter is mild. In tropical regions, the plants grow year-round and self-seed or spread through sucker growth.


  • Castor bean plants should be planted with caution. They are highly toxic. One castor bean seed will kill a child and several seeds will kill an adult, according to Dr Thomas Obrello of the Union Community College Biology Department in New Jersey.
  • Never plant castor beans where children play.

About the Author


Based in Oregon, Kimberly Sharpe has been a writer since 2006. She writes for numerous online publications. Her writing has a strong focus on home improvement, gardening, parenting, pets and travel. She has traveled extensively to such places as India and Sri Lanka to widen and enhance her writing and knowledge base.