Grass tree (Yacca)

Xanthorrhoea australis

Iconic Australian endemic with a thick blackened fire-shaped trunk topped by a fountain of long grass-like leaves and, in mature specimens, a tall flower spike of cream flowers in early summer.

Hardiness ratings

Grass tree (Yacca) hardiness across the four zone systems
SystemRatingTemperature rangeHow to read it
USDA hardiness zone Zone 9–10 −6.7 °C to 4.4 °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 3–6 −5 °C to 15 °C Plant tolerates down to this zone

Growing notes

  • Native to southeastern Australia — found across Victoria, Tasmania, NSW, and southeastern Queensland
  • Extraordinarily slow growing — trunk growth is approximately 1 cm per year, so a 2 m specimen is around 200 years old; never harvest wild plants, only buy nursery-propagated stock with provenance
  • Fire-adapted — the blackened trunk results from periodic fires, which often trigger flowering
  • Cultural significance to Aboriginal peoples — the resin was historically used as adhesive, the flower spike for fishing spears

Categories

Related plants

Cross-check Grass tree (Yacca) against your zones

Reference

Grass tree (Yacca) on Wikipedia