Not edible
Deadly poisonous. The seeds contain ricin: a single chewed seed can seriously harm a child, and a few can be fatal. All parts are toxic if eaten, and handling the leaves can irritate skin. Toxic to dogs, cats and horses. Keep children and pets away, wear gloves when handling seed, and pinch off the young seed pods so no seeds ripen.
Castor Bean
Ricinus communis
Start castor bean indoors 6 weeks before your last spring frost, then plant out 2 weeks after your last spring frost. Space plants 36 in (91 cm) apart.
Photo: Alvesgaspar, CC BY-SA 3.0 · source
When to plant
Timed from your frost dates, so it holds wherever you garden. Give yours and every step below becomes a date.
Optimal Indoor Start
From seedRecommended- Start indoors6 weeks before your last spring frost
- Begin hardening off1 week after your last spring frost
- Plant out2 weeks after your last spring frost
- First harvestsummer to fall, once established
Optimal Direct Sow
From seed- Sow outdoors2 weeks after your last spring frost
- First harvestsummer to fall, once established
Growing castor bean
- Spacing in the row
- 36 in (91 cm)
- Between rows
- 48 in (122 cm)
- Planting depth
- 1/2-1 inch; soak or nick the seed overnight first
- Sun
- Full Sun
- Soil
- Deep, rich, moist, well-drained
- Germination
- 7-21 days at 65-75°F
- Harvest season
- Summer to Fall
- Mature height
- 6-10 feet
- Support
- Stake if top-heavy; shelter from strong wind.
- Hardy to
- USDA zone 9
- Life cycle
- Perennial
Soak seed overnight, sow singly 1 inch deep in pots; wear gloves and wash hands after handling seed.
Watering. Water generously while growing; established plants tolerate some drought.
Feeding
- Growing
- Feed generously during the season for the largest plants.
- How often
- Every 4 weeks during active growth. Work a complete fertilizer or compost in at planting; these fast-growing plants reach full size only on fertile, well-watered soil.
Your castor bean, planned to the day.
Canopy turns these timings into dates from your own frost data, places every plant at its spacing on your garden map, and tracks it all the way to harvest.