Climbing hydrangea

Hydrangea anomala subsp. petiolaris

Self-clinging deciduous East Asian climber with rounded leaves and broad flat heads of small fertile flowers ringed by larger sterile florets in early summer. The principal climber for north-facing walls.

Hardiness ratings

Climbing hydrangea hardiness across the four zone systems
SystemRatingTemperature rangeHow to read it
USDA hardiness zone Zone 4–8 −34.4 °C to −6.7 °C Plant tolerates down to this zone
RHS hardiness rating H7 down to −20 °C Plant needs at least this level of cold tolerance
Canadian plant hardiness zone Zone 4–8 −29 °C to −1 °C Plant tolerates down to this zone
Australian (ANBG) zone Zone 2–5 −10 °C to 10 °C Plant tolerates down to this zone

Growing notes

  • Plant against north-facing walls and shaded fences — succeeds where most flowering climbers fail, eventually 10 m or more
  • Self-clinging with aerial rootlets — needs no support, but slow to start (3–5 years before significant climbing)
  • Distinct from the shrubby hydrangeas already in the database — H. anomala is the true climbing species
  • Cinnamon-coloured exfoliating bark provides secondary winter interest on mature stems

Pet caution: Climbing hydrangea 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 Climbing hydrangea against your zones

Reference

Climbing hydrangea on Wikipedia