How to Grow Ricinus Plants

Guide to Growing Castor Oil Plant, Castor Bean and Palma Christi

Ricinus plants are half hardy perennials that range from 90 cm to 1.8 m (3 to 6 feet) in height.

They are an erect plant that carry large lobed leaves; these may be red, bronze, green or purple in colour.

They bloom in the middle of summer when they carry clusters of red or green flowers.

They then produce attractive seed pods. Some common names for Ricinus include Castor Oil Plant, Castor Bean plant and Palma Christi.

Castor oil plant
Castor oil plant by BY-YOUR-⌘; Creative Commons.

Ricinus communis
Ricinus communis (fruit) by Pizzodisevo; Creative Commons.

Ricinus Plant Growing and Care Guide

Common Names: Castor Oil Plant, Palma Christi, Castor Bean, Mamona, Jada, Arandi, Higuerilla.
Family: Euphorbiaceae.
Life Cycle: Half hardy perennial commonly grown as a half hardy annual by gardeners.
Height: 40 to 470 inches (100 to 1200 cm).
Native: Mediterranean, East Africa, South Asia.
Growing Region: Zones 3 to 10. As a perennial in zones 8 to 10.

Flowers: Summer.
Flower Details: Red, yellow, green. Terminal panicle. Monoclinous.
Foliage: Red, purple, green. Glossy. Palmate.
Fruit: Round. Spiky. Red, Purplish-green, green.

Sow Outside: 1/4 inch (6 mm). Following the last frost in warm areas. Spacing 24 to 60 inches (60 to 150 cm).
Sow Inside: Soak bean for one day. Use peat pots. Germination time: two to three weeks. Temperature 70°F (21°C). Seven or eight weeks in advance. Transplant outdoors a couple of weeks after the last frost.

Requirements: Full sunlight. Good drainage. For best results: soil pH 6 to 7. Rich soil. Moist soil. Sandy soil. Provide support. Regular feed. Regular watering..
Species Growing Guide: Ricinus communis the Castor Bean

How to Grow Castor Oil Plant and other Ricinus Plants in the Garden

It is best to start off Castor Oil plants indoors. First soak the Castor oil seeds for a day in warm water, then sow the seeds about 6 mm (1/4 inch) deep into peat pots about six weeks before the last frost.

Ricinus Plant seeds should take about two or three weeks to germinate at 21 to 25 degrees Centigrade (70 to 77°F).

The young Castor oil seedlings should then be transplanted outdoors a couple of weeks after the last frost.

Ricinus species should be spaced from 70 cm (small) to 1.5 m (large) apart, and grown in a sunny part of the garden. For best results grow Castor oil plants in a rich loam of pH 6 to 7.

Caring for Caster Oil Plants - Ricinus

Castor Oil Plants and other Ricinus plant species are easy to look after; they like a moist soil so water regularly. They are big plants so provide a stake and feed them regularly.

Common Questions

How many members does the Ricinus genus contain?

The Ricinus plant genus has only one species, which is commonly known as the Castor oil plant.

Do Ricinus members make a good garden or landscaping plant?

Yes, Ricinus communis can be a dramatic addition to a garden due to its large, glossy foliage, and unique seed pods, but it must be handled with care due to its toxicity.

Which Ricinus species are most frequently grown?

As there is only one species, Ricinus communis is the one grown. It has many cultivated varieties differing in size and leaf color.

Are Ricinus plants fragrant?

Ricinus plants are not known for their fragrance, they are usually grown for their striking appearance.

What is the perfect location to grow Ricinus?

Ricinus communis thrives in a sunny location with well-drained soil. It is a tropical plant that prefers warm climates.

Is Ricinus invasive in the USA, if so in which states?

Currently, Ricinus communis is not officially listed as invasive in the USA, but it can naturalize and become problematic in some areas.

How do I remove Ricinus plants from my garden?

When removing Ricinus, use gloves to protect your skin from the plant's toxic sap. Dig up the entire plant, making sure to remove all roots.


The Ricinus genus comprises the castor oil plant, which is native to the Mediterranean region and East Africa. It is known for its glossy foliage and large, spiked seed pods.

Ricinus plants thrive in full sun and rich, well-drained soil. They are generally planted in late spring, after the risk of frost has passed. While they are hardy in warm climates, in colder regions they are often grown as annuals due to their fast growth rate.

I hope that you enjoyed this guide on how to grow Ricinus plants. You may also enjoy the following Gardener's HQ growing guides: How to grow Menyanthes and Aleurites moluccana plants.