Hong Kong orchid tree

Bauhinia × blakeana

Sterile hybrid orchid tree with large magenta-purple orchid-like flowers in autumn and winter, on a small tree to 8 m with characteristic bilobed butterfly-leaves. The floral emblem of Hong Kong.

Hardiness ratings

Hong Kong orchid tree hardiness across the four zone systems
SystemRatingTemperature rangeHow 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 4–7 0 °C and warmer Plant tolerates down to this zone

Growing notes

  • Hybrid of B. variegata × B. purpurea, originally discovered as a single tree in Hong Kong in 1880 — all cultivated specimens are clones of that original tree
  • Floral emblem of Hong Kong — depicted on the territory’s flag
  • Sterile — does not set seed, so far safer than B. variegata (already in the database from batch 8) where that species is invasive
  • Frost-tender — subtropical cultivation only
  • 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.

Categories

Related plants

Cross-check Hong Kong orchid tree against your zones

Reference

Hong Kong orchid tree on Wikipedia