Castor Bean in Zone 11a & 11b
Ricinus communis
When to plant castor bean in zone 11b
Zones 11a and 11b share the same average frost dates in our data, so this page covers both.
Method: Direct sow: Direct-sow outside. Castor Bean doesn't transplant well, or doesn't need the extra time indoors.
| Start indoors | Not typically started indoors |
|---|---|
| Direct sow / transplant outside | Jan 8–Jan 15 |
| Estimated bloom | Apr 18–Apr 25 (~100 days after direct-sowing) |
Spacing: about 10 square feet per plant (square-foot-gardening spacing). Mature height: 6-10 ft.
Castor bean is included here so this site can state plainly what it is, rather than leaving a gardener to find out from a packet that does not say.
How castor bean fits zone 11's season
Zone 11b is frost-free in this dataset, so frost is not what limits the calendar here. What you can plant, and when, comes down to summer heat and daylength instead.
Good companions
No standout companions recorded yet for Castor Bean.
Where to buy castor bean seeds
See why we recommend these suppliers →
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See it growing
Search YouTube for "growing castor bean" videos → (a live search, not a hand-picked video; results vary and aren't vetted by us)
← Back to the full zone 11b calendar · Full companion planting guide · Full plant profile · Plan your beds in the Garden Designer →
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Growing Castor Bean in USDA zone 11b: when to start seeds indoors, when to direct-sow, and when to expect a bloom.
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