Tall single-stemmed South African aloe reaching 3 m with thorny grey-green sword leaves and dramatic candelabra of orange flower spikes in winter. The commercial source of "Cape aloes" laxative bitters.
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 | H2 | 1 °C to 5 °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 3–7 | −5 °C and warmer | Plant tolerates down to this zone |
Growing notes
- Native to the Eastern Cape and KwaZulu-Natal of South Africa — adapted to summer-rainfall and Mediterranean climates
- Distinct from Aloe vera already in the database — A. ferox is much larger, single-stemmed, and the source of bitter Cape aloe laxative rather than soothing aloe gel
- Winter-flowering — important nectar source for sunbirds and other African nectarivorous birds
- Drought tolerant once established
- Not reliably hardy outdoors in Canada — Canadian zone values shown represent the system maximum and do not imply garden cultivation north of the warmest coastal pockets.
Pet caution: Bitter aloe (Cape aloe) is listed as potentially harmful to cats and/or dogs. Keep pets from grazing on it, and contact a vet if you suspect your animal has eaten some.
Categories
Related plants
Cross-check Bitter aloe (Cape aloe) against your zones