Coastal she-oak

Casuarina equisetifolia

Tropical and subtropical pioneer she-oak of coastal sands across the Australian, Pacific, and Indian Ocean tropics. Tall, narrow, salt- and wind-tolerant — among the great pioneer beach windbreak species.

Hardiness ratings

Coastal she-oak hardiness across the four zone systems
SystemRatingTemperature rangeHow to read it
USDA hardiness zone Zone 9–12 −6.7 °C to 15.6 °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

  • Premier tropical coastal windbreak — salt tolerant, wind tolerant, tolerates pure sand, fixes nitrogen via actinorhizal Frankia bacteria like other Casuarinas
  • Distinct from the river she-oak Casuarina cunninghamiana (already in the database as `she-oak`) — coastal she-oak is the tropical coastal species, river she-oak is the inland riverbank species
  • WARNING: Listed INVASIVE in southern Florida, Hawaii, and parts of the Caribbean — has displaced native dune and beach communities, do not plant outside its native range in those regions
  • Whispering needle-like foliage in even the lightest breeze — gives the genus the Australian common name "she-oak" (for its supposed similarity to the wind in an English oak)
  • 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 Coastal she-oak against your zones

Reference

Coastal she-oak on Wikipedia