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Ricinus communis

Image of Ricinus communis

James H. Schutte

Family

Euphorbiaceae

Botanical Name

Ricinus communis

Plant Common Name

Castorbean

General Description

So why would gardeners grow such a deadly poisonous plant as a garden ornamental? Showy forms of castor bean are bold, brightly colored and thrive in high heat and drought. In tropical regions castor bean grows as a tall evergreen subshrub, but in temperate zones it is commonly grown as an annual/tender perennial. This native of northern Africa and western Asia has become naturalized in many tropical to subtropical regions across the globe where it is considered invasive. Some Third World countries grow it as a crop plant for castor oil, though the extraction process is messy and toxic.

Ornamentally, it's grown for it large, bold, sharply lobed leaves that come in shades of green, purple, or bronze. In summer, spikes of red flowers are produced followed by spiny, oval, red to brown fruit capsules. These should be removed because the seeds within the capsules are highly dangerous and look like beans to children.

Castor bean grows best in full sun and average to poor, well-drained soil. It makes a bold, colorful accent for mixed borders and annual beds. It becomes very large and bushy, so be sure to provide it ample space. Plants are very frost sensitive and will quickly die when the cold comes. Discard in the garbage and refrain from composting castor bean. Do not grow it where children play because it poses serious health concerns. To learn more about its toxicity go to: http://bit.ly/bcpK8k

Numerous burgundy-leaved, red-fruited cultivars of castor bean have been selected, including 'Sanguineus' and ‘Carmencita Bright Red’.

Characteristics

  • AHS Heat Zone

    12 - 1

  • USDA Hardiness Zone

    11 - 14

  • Sunset Zone

    H1, H2, 23, 24

  • Plant Type

    Shrub

  • Sun Exposure

    Full Sun, Partial Sun

  • Height

    5'-30' / 1.5m - 9.1m (10)

  • Width

    4'-5' / 1.2m - 1.5m (3)

  • Bloom Time

    Early Summer, Summer, Late Summer

  • Native To

    Northern Africa, Western Asia

Growing Conditions

  • Soil pH

    Acidic, Neutral, Alkaline

  • Soil Drainage

    Well Drained

  • Soil type

    Clay, Loam, Sand

  • Tolerances

    Pollution, Drought, Salt

  • Growth Rate

    Fast

  • Water Requirements

    Drought Tolerant, Average Water

  • Habit

    Upright/Erect

  • Seasonal Interest

    Summer, Fall

Ornamental Features

  • Flower Interest

    Insignificant

  • Flower Color

    White, Yellow, Green

  • Fruit Color

    Red, Sandy Brown

  • Foliage Color (Spring)

    Purple, Light Green, Dark Green, Bronze

  • Foliage Color (Summer)

    Red, Purple, Dark Green, Burgundy

  • Foliage Color (Fall)

    Red, Purple, Dark Green, Burgundy

  • Foliage Color (Winter)

    Red, Purple, Dark Green, Burgundy

  • Bark Color

    Green, Brown

  • Fragrant Flowers

    No

  • Fragrant Fruit

    No

  • Fragrant Foliage

    No

  • Bark or Stem Fragrant

    No

  • Flower Petal Number

    Single

  • Repeat Bloomer

    No

  • Showy Fruit

    Yes

  • Edible Fruit

    No

  • Showy Foliage

    Yes

  • Foliage Texture

    Bold

  • Foliage Sheen

    Glossy

  • Evergreen

    Semi-Evergreen

  • Showy Bark

    No

Special Characteristics

  • Bark Texture

    Smooth

  • Usage

    Bedding Plant, Container, Feature Plant, Mixed Border, Tropical

  • Sharp or Has Thorns

    No

  • Invasive

    Yes

  • Self-Sowing

    Yes