What is a Castor Oil Plant?

Mary McMahon
Mary McMahon

A castor oil plant is a shrub native to the Mediterranean region of the world. This plant has been cultivated for ornamental and medicinal regions since Ancient Egyptian times, as castor seeds found in the tombs of notable Egyptians testify. As the name of the plant suggests, castor oil is produced from the seeds and this product is available at health food stores in addition to being found compounded in a number of different products.

Many believe that topical castor oil can reduce the appearance of spider veins.
Many believe that topical castor oil can reduce the appearance of spider veins.

This flowering plant has palmate serrated leaves, varying in color from a dark and glossy green to a dull red. The flowers grow in upright spikes, later developing into seeds known as castor beans, covered by a spiky outer coating. Castor beans are not true beans, as these plants are not members of the bean family, but they superficially resemble beans. Seeds from the castor oil plant are sometimes used as beads in jewelry. A similar plant known as the false castor oil plant looks similar, but does not have the same properties.

Castor oil may be used to induce labor in some situations.
Castor oil may be used to induce labor in some situations.

Ricins communis, as it is formally known, grows well in the United States in USDA zones nine through 11. It prefers full sun to part shade and well drained soil. Because the castor oil plant can grow very rapidly and produce large foliage, it is advisable to plant it in an area where overshading of smaller plants is not a concern. Gardeners may also want to avoid the castor oil plant if they have pets or toddlers, due to concerns about the toxicity of the seeds; curious animals and children may chew the seeds or pods and become very sick.

In their natural form, castor seeds are toxic. They contain a highly potent toxin known as ricin. Consuming a few seeds can have very deleterious effects and can sometimes be deadly. However, if the seeds are cold pressed to extract the oil, it is possible to generate a product safe for human consumption. The ricin is released by heat, and as along as the beans are not heated during processing, it will remain trapped inside.

Castor oil has historically been used as a purgative. While it is safe to consume, it can irritate the intestines and may act to resolve constipation. It was also applied topically to the skin by some cultures. Today, castor oil is used in food processing in some regions, particularly in the development of food coatings. It is used in trace amounts and should not cause irritation to people who consume these products. Castor oil can also be used in the production of fuels.

Mary McMahon
Mary McMahon

Ever since she began contributing to the site several years ago, Mary has embraced the exciting challenge of being a wiseGEEK researcher and writer. Mary has a liberal arts degree from Goddard College and spends her free time reading, cooking, and exploring the great outdoors.

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Discussion Comments


It is good to know that the castor oil plant may be toxic to pets and children. Even though I live in an area where this plant is grown, I would not want to plant it where I live.

I have a daycare in my home, and also have two dogs that like to play outside. The last thing I need is someone getting sick from being curious about this plant.

I am familiar with the many uses of this oil and buy castor oil through my food co-op. One bottle of this will last me for several months and costs less than $10.


I am most familiar with medicinal castor oil uses, but would also love to grow this as an ornamental plant. Fortunately I live in a place where this would do real well, and I am always looking for something that is both decorative and functional to grow.

If I got real ambitious I would try to harvest some of the castor oil myself, but I also have a large area that needs some filling in and this plant sounds like it might be the perfect solution.


I was first introduced to castor oil when I was reading a book about menopause and they talked about using castor oil packs for various symptoms.

If you pour some castor oil on a piece of fabric, warm it up and apply it to your abdomen for about 20 minutes, it can help relieve pain and cramping on your abdomen.

I was a little bit skeptical about this wondering how an oil like this could really make a difference, but it worked for me. I don't know if it was a combination of the oil and taking the time to relax, but my cramping went away and I felt so much better and more relaxed.


I have never seen a castor bean plant growing and probably wouldn't even recognize it even if I did. It would be pretty rare to see one growing where I live since I don't live in a very warm growing zone. I live in zone 5 and there is no way this plant would make it through the winter.

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