Black wattle

Acacia mearnsii

Fast-growing Australian wattle widely planted as a commercial tannin source. The bark contains the highest commercially viable tannin concentration of any common species (28–40%).

Hardiness ratings

Black wattle hardiness across the four zone systems
SystemRatingTemperature rangeHow to read it
USDA hardiness zone Zone 8–11 −12.2 °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 3–7 −5 °C and warmer Plant tolerates down to this zone

Growing notes

  • Tannin extracted from the bark — the principal world source of vegetable tannin for the leather industry, with plantations concentrated in South Africa, Brazil, and East Africa
  • Distinct from the related wattles already in the database — golden wattle (A. pycnantha), silver wattle (A. dealbata), blackwood acacia (A. melanoxylon) — A. mearnsii is grown specifically for bark tannin
  • WARNING: Listed INVASIVE in southern Africa, parts of southern Europe, and the Pacific — escaped from plantations to displace native vegetation, do not plant outside its native eastern Australian range or established plantations
  • Nitrogen-fixing legume — improves soils where it grows

Categories

Related plants

Cross-check Black wattle against your zones

Reference

Black wattle on Wikipedia