How to Grow Castor Bean Plants

About Castor Bean Flower and Deadly Ricin

The Castor Bean (Ricinus) flower is well known for a couple of reasons. As gardeners, let’s focus on the bold, decorative foliage, that makes this plant so attractive in garden settings. However, you must also be aware that the beans of this plant are very poisonous. It can be used to make Ricin, a deadly poison. It is so dangerous that with this in mind if you have access to castor bean seeds and decide to grow them, be ever vigilant to keep children n pets away from this plant. Seed companies voluntarily took this seed off the market decades ago. However, they now have returned to the market.

Native to tropical Africa, this plant has bold, palm-shaped leaves with striking red flowers. Other flower colors include green and a pinkish red. Different varieties of this plant grow from 5 to 15 feet tall. Used as an ornamental plant, it is sometimes grown indoors as a houseplant in large, floor containers.

Both seeds and plant parts are poisonous for people, animals, and insects through ingestion. Skin contact can cause initiation and allergic reactions. The deadly poison “Ricin” is made from the seeds.

Castor oil is an extract from the plant seeds. The process does not produce ricin.

If you grow this plant, do so responsibly. We strongly recommend you do not let the flowers go to seed.

Did you Know? African natives once wore necklaces made from this plant!

The Castor Bean plant is also known as Castor Oil Plant, Mole Bean Plant, and the African Wonder Tree.

Note: Because deadly Ricin is made from this plant, most seed manufacturers no longer carry the seeds for home gardens. They discontinued selling these seeds right after 2000.

Castor Bean Plant Specifications

Flower Colors: Greenish-yellow. The seed ods are bright red or pink.

Flowers Bloom: Mid-Summer through Fall.

Plant Height: Five to fifteen feet.

Light Requirements: Full sun.

Ideal Soil pH: 4.5 – 8.3. This is a fairly broad range.

Hardiness Zone: 9 – 11.

Toxicity: Can be very toxic and fatal.

Native To: Africa and the Middle East.

Plant Type: Annual

Botanical Name: Ricinus communis

Are Castor Beans Edible?

NO!!

Although there is a way to prepare them to make edible in small amounts, we recommend you not attempt it. Caster beans can cause many serious medical problems and can result in death. We strongly recommend that you DO NOT attempt to prepare them for consumption.

Medicinal Uses for Castor Beans

The beans are used to make castor oil. The oil is free of dangerous Ricin.

Castor Bean Plant Propagation

Castor Bean plants are grown from seed. Directly sow Castor Bean seeds into your flower garden after the last frost date in your area.

Keep the soil well-watered.

How to Grow Castor Bean Flowers

Castor Bean plants are easy to grow. They prefer full sun and a rich, well-drained soil. Add plenty of compost before planting them. These tropical plants prefer warm weather, above 60 degrees.

Castor Bean plants grow quickly. Depending upon the variety you have, they will grow 5-15 feet tall. Water them during dry periods, once or twice per week. Add a general-purpose fertilizer once a month. Add mulch to help retain soil moisture and keep weeds down.

Do not let the flowers go to seed, as it is the seed that contains toxic Ricin. Some people remove flower buds and just enjoy the beauty of the plant. Otherwise, deadhead flowers as soon as they have died.

Frost and freeze will kill these tropical plants.