Tropical shrub historically the world's premier source of natural blue dye — driving global trade for centuries until synthetic indigo replaced it in the 1880s.
Hardiness ratings
| System | Rating | Temperature range | How to read it |
|---|---|---|---|
| USDA hardiness zone | Zone 9–11 | −6.7 °C to 10 °C | Plant tolerates down to this zone |
| RHS hardiness rating | H3 | −5 °C to 1 °C | Plant needs at least this level of cold tolerance |
| Canadian plant hardiness zone | Zone 9 | −1 °C and warmer | Plant tolerates down to this zone |
| Australian (ANBG) zone | Zone 5–7 | 5 °C and warmer | Plant tolerates down to this zone |
Growing notes
- Drought tolerant once established
- Dye extraction is a multi-day fermentation process — interesting craft project but not a casual harvest
- Pink-purple pea flowers; foliage rather than flowers carries the dye precursor
Categories
Related plants
Cross-check True indigo against your zones