1 named cultivar
The Story
Plant Bio
Ricinus communis, commonly known as castor bean, is a fast-growing, large shrub with decorative foliage and clusters of flowers.
Contains seeds that produce castor oil; all parts of the plant are toxic if ingested.
Uses & Benefits:
Essentials
At a Glance
Plant Type
Annual
Height
120 inches
Width
72 inches
Light
Full Sun, Partial Sun
Zones
9, 10
Water
Moderate to high
Humidity
Prefers moderate humidity
Lifespan
Perennial in warm climates
Native To
Tropical East Africa
Toxicity
Highly toxic if ingested
Planting
How to Grow
- Select a sunny location with well-draining soil for planting.
- Tuck seeds about 1 inch deep into moist soil in early spring.
- Mist cuttings regularly to maintain humidity and encourage rooting.
- Transplant seedlings once they are sturdy, after 4-6 weeks, when danger of frost is past.
- Water consistently during dry spells to promote healthy growth.
- Apply a balanced fertilizer monthly during the growing season.
Pro Tip
Soak seeds overnight before planting to improve germination rates.
Keep It Thriving
Care Guide
Do
- Water deeply and regularly during hot summer days 🌱
- Apply organic compost annually to enrich soil
- Prune to remove dead or damaged leaves for better airflow
Don't
- Avoid overwatering to prevent root rot ❌
- Do not expose young plants to frost
- Refrain from using chemical pesticides excessively
Seasonal Care Calendar
| Task | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Fertilize | ||||||||||||
| Plant | ||||||||||||
| Winter Prep |
Watch Out For
Pests & Diseases
Common Pests
Common Diseases
In the Garden
Landscape Uses & Companions
Landscape Uses
Companion Plants
Multiply
Propagation Methods
Good to Know
Common Questions
Castor Bean questions
What zones can Castor Bean grow in?
Castor Bean is hardy in USDA Zones 9–10. Inside that range it survives winter in the ground; outside it, grow it as an annual or a container plant you protect.
Is Castor Bean deer resistant?
Not reliably. Deer may browse Castor Bean, especially tender spring growth — plan on repellents or fencing where pressure is high.
When does Castor Bean bloom?
Castor Bean typically blooms in late summer through early fall. Exact timing shifts a week or two with your zone — Sow's bloom calendar maps it to your garden.
Does Castor Bean need full sun?
Castor Bean does best in full sun to part shade. In hot climates, afternoon shade keeps blooms fresher longer.
Is Castor Bean drought tolerant?
Yes — once established (usually after the first full season), Castor Bean handles dry spells with minimal watering. Water deeply its first year to build the root system that makes that possible.
More Ricinus to compare
Keep exploring
Explore the genus
Hardy in your zone?
Grow Castor Bean with confidence
See it in a design of your actual yard, get zone-matched care reminders, and track it season by season in your garden journal.