Growing Guide
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Castor Bean

Annual Flower

Ricinus communis
Euphorbiaceae Family

Huge plants (up to 10 feet tall) with large, coarse-textured leaves bring a bold, tropical look to the garden. A good annual to create height quickly or as a background for smaller plants. Caution: Entire plant (and especially the seeds) are poisonous.

Site Characteristics
  • full sun

Soil conditions:

  • requires well-drained soil
Performs best in rich soil that is moist but well-drained.
Plant Traits

Lifecycle: annual

Ease-of-care: easy

Height: 4 to 10 feet

Spread: 2 to 5 feet

Bloom time:

  • mid-summer
  • late summer

Flower color: inconspicuous

Foliage color:

  • medium green
  • dark green
  • other

Depends on variety. Colors include purple-red, red-brown, and green.

Foliage texture: coarse

Leaves are 1 to 1.5 feet wide and have 5 to 12 lobes.

Shape: upright

Shape in flower: same as above

Special Considerations
Special characteristics:
  • deer resistant
  • non-aggressive
  • non-invasive
  • not native to North America - Native to Africa.
  • bears ornamental fruit - Burred seed campsules are red and showy. Seeds are very poisonous.
Special uses:
  • direct-seeding
Growing Information
How to plant:

Propagate by seed - Start seeds outdoors after spring frost danger has passed, or indoors 6 to 8 weeks before the last spring frost.

Germination temperature: 70 F to 75 F

Days to emergence: 14 to 21

Maintenance and care:
Plants may need staking. Fertilize if soil is infertile.

More growing information: How to Grow Annuals

‘Carmencita Pink’: 5’ tall plants with pink seed heads.

‘Impala’: young growth is maroon and showy.

‘Sanguineus’: 8’ tall plants have leaves with reddish tones.

‘Zanzibariensis’: 10 to 15’ tall fast growing plants with deep green leaves.