Castor bean
Ricinus communis · Euphorbiaceae
The gardener's calendar
In autumn, ease off feeding and take the chance to clean up around castor bean and prepare for winter.
ID card
- Foliage
- Deciduous
- Flowering
- Summer to fall
- Adult size
- 1.5 to 3 m in height
- Growth
- Very fast
- Hardiness
- Tender (0 to 5 °C minimum)
- Exposure
- Full sun
- Origin
- Tropical Africa
- Soil type
- Well-draining, rich
Care
Exposure
Castor bean thrives in full sun to develop its spectacular foliage and robust structure. It tolerates partial shade but growth will be less vigorous. Install it in an open location, as it also appreciates heat.
Watering
Water regularly during the growing season (spring and summer), keeping the substrate moist without waterlogging. Reduce watering in fall and winter. In pots, check that water drains well and doesn't stagnate.
Substrate and soil
Use rich, well-draining potting soil, enriched with compost or organic matter. Castor bean appreciates fertile soils that promote its spectacular growth. In the ground, loosen the soil before planting.
Fertilizer
Apply balanced fertilizer every 15 to 20 days during active growth. An extra dose of potassium stimulates fruiting and strengthens the structure. Reduce applications in fall.
Pruning and structure
Castor bean doesn't require specific pruning but can be cut back in spring to control its height and encourage branching. Remove damaged or diseased leaves as needed. Wear gloves when handling.
Pests and diseases
Castor bean is generally little affected, but watch for spider mites in dry climates and whiteflies indoors. In case of excess moisture, root rot may occur: improve drainage and reduce watering. Quickly isolate any infested plant.
Did you know?
Castor bean has a fascinating history: used since ancient Egypt for castor oil, it became a highly prized ornamental plant in the nineteenth century. Its scientific name Ricinus means "tick" in Latin, because the seed resembles a mite. It's also an extraordinarily productive species: a single plant can generate thousands of seeds in one season.
Where to buy it
Best planted in autumn so the roots settle in before summer, or in early spring once the frost has passed. Pick a plant with healthy foliage and roots that are not exposed. Best time: March, October, November.
Add this plant to my garden →Plants from the same family
- Wood spurgeEuphorbia amygdaloides
- Caper spurgeEuphorbia lathyris
- Albanian spurgeEuphorbia characias
- Spiny spurgeEuphorbia spinosa
- Garden crotonCodiaeum variegatum
- Griffith's spurgeEuphorbia griffithii
Tips generated and checked by Viridia — adapt them to your local climate.