Castor Oil Plant, Castor Bean Plant 'Gibsonii'

Ricinus communis

Family: Euphorbiaceae (yoo-for-bee-AY-see-ee) (Info)
Genus: Ricinus (RISS-i-nus) (Info)
Species: communis (KOM-yoo-nis) (Info)
Cultivar: Gibsonii
Synonym:Ricinus communis var. gibsonii
Synonym:Ricinus gibsonii



Foliage Color:


Bloom Characteristics:

Unknown - Tell us

Water Requirements:

Average Water Needs; Water regularly; do not overwater

Where to Grow:

Unknown - Tell us


36-48 in. (90-120 cm)

4-6 ft. (1.2-1.8 m)

6-8 ft. (1.8-2.4 m)

8-10 ft. (2.4-3 m)


36-48 in. (90-120 cm)


USDA Zone 8a: to -12.2 C (10 F)

USDA Zone 8b: to -9.4 C (15 F)

USDA Zone 9a: to -6.6 C (20 F)

USDA Zone 9b: to -3.8 C (25 F)

USDA Zone 10b: to 1.7 C (35 F)

USDA Zone 11: above 4.5 C (40 F)

Sun Exposure:

Full Sun


All parts of plant are poisonous if ingested

Bloom Color:


Bloom Time:

Late Summer/Early Fall


Grown for foliage


Other details:

May be a noxious weed or invasive

Soil pH requirements:

Unknown - Tell us

Patent Information:

Unknown - Tell us

Propagation Methods:

From seed; direct sow after last frost

Self-sows freely; deadhead if you do not want volunteer seedlings next season

Seed Collecting:

Bag seedheads to capture ripening seed

Properly cleaned, seed can be successfully stored


This plant has been said to grow in the following regions:

Redding, California

Peyton, Colorado

Meriden, Connecticut

Cape Canaveral, Florida

New Port Richey, Florida

Alden, Kansas

Barbourville, Kentucky

Southold, New York

Waverly, New York

Hulbert, Oklahoma

West Newton, Pennsylvania

Sherman, Texas

show all

Gardeners' Notes:


On Mar 2, 2016, coriaceous from ROSLINDALE, MA wrote:

This species has naturalized in 34 states. As far north as Maine, it can overwinter as a self-sowing annual.

Where it is hardy, it's a suckering perennial shrub that can reach a height of 40'.

It's a heavy producer of light air-borne pollen which is highly allergenic. It's a common trigger for hayfever and asthma. In many people, it also causes a skin rash on contact. The seed pods are spiny.

In California, Florida, and Texas, it's on the official lists of species invasive of natural habitat.

Native to the eastern Mediterranean, east Africa, and India, it's now spread to most tropical areas around the world, where it's commonly considered invasive.


On Jun 20, 2009, griffinpd from Sherman, TX (Zone 7b) wrote:

The first time I saw this plant I knew that I MUST have it. That moment was definitely a "SEE"! I now have about 20 reds and 20 purples. I use them as a backdrop for my hibiscus plants.

I initially started my seeds inside but soon discovered that the seeds that I sowed straight into the ground soon caught up with the potted plants. (Very close to 100% germination rate) They definitely grow like weeds and go crazy from the water and fertilizer that my hibiscus get.


On Mar 5, 2007, berrygirl from Braselton, GA (Zone 8a) wrote:

Introduced into English gardens in the 16th century. Stately quick-growing ornamental plant with tropical appearance, large reddish-tinged foliage and brightly colored seedpods, a real head-turner. Listed in 1896 catalog of R & J Farquhar along with 10 other named varieties. SEEDS AND SEEDPODS ARE POISONOUS!
Annual, 6-8' tall.