Cork oak

Quercus suber

Mediterranean evergreen oak of southern Iberia and North Africa, with deeply furrowed thick corky bark that can be stripped sustainably from the living tree on a 9–12 year cycle. The world source of natural wine-bottle corks.

Hardiness ratings

Cork oak hardiness across the four zone systems
SystemRatingTemperature rangeHow to read it
USDA hardiness zone Zone 8–10 −12.2 °C to 4.4 °C Plant tolerates down to this zone
RHS hardiness rating H4 −10 °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 3–6 −5 °C to 15 °C Plant tolerates down to this zone

Growing notes

  • Corky bark stripped from the trunk every 9–12 years from trees over 25 years old — a non-destructive harvest the tree survives and regenerates from over a 200+ year working life
  • The cork oak forests (montados, dehesas) of Portugal, Spain, Morocco, Algeria and Tunisia are an exceptional silvopastoral ecosystem and a UNESCO biosphere reserve in several regions
  • Distinct from English oak (Q. robur, already in the database) — cork oak is evergreen, drought-tolerant, and not frost-hardy, suited only to Mediterranean climates
  • Drought tolerant and fire-resistant once mature — corky bark is excellent insulation against summer fires

Pet caution: Cork oak 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 Cork oak against your zones

Reference

Cork oak on Wikipedia