Cork Oak (Quercus suber)
 
Cork Oak is a slow-growing evergreen oak famous for its thick, deeply furrowed bark, which is harvested to make cork for wine bottles, bulletin boards, and more. Over time, the bark develops a gnarly, rugged texture that gives the tree an ancient look even while young—perfect for bonsai artists who value bark character. The small, leathery leaves stay evergreen in mild climates and hold up well to pruning.
 
As a Bonsai:
Cork Oak is a subtropical species well-suited for bonsai, especially for growers who like a long-term project. It responds well to pruning and training and builds taper and bark character slowly but steadily. While it can be grown indoors during winter, it performs best with plenty of outdoor sun during the growing season.
 
📢 This is a subtropical species—it thrives in warm temperatures during the growing season and should be grown outdoors in warmer months. It should be brought indoors when night temperatures approach 40°F. For optimal health, it benefits from a short pseudo-dormancy period during winter, with at least a month of daytime temperatures around 55–65°F.
 
Plant Features:
Hardiness Zone: 8–11 (must be overwintered indoors in colder climates)
Growth Habit: Upright, irregular branching; moderate to slow growth
Mature Size: 40–60 ft in the landscape; suitable for medium to large bonsai
Foliage: Small, leathery, dark green evergreen leaves with slightly serrated edges
Bark: Thick, corky bark that develops deeply furrowed texture with age; harvested commercially
Sun Requirements: Full sun for best bark and foliage health
Soil Type: Well-draining, sandy or loamy soil preferred
Water Needs: Moderate; prefers occasional dry cycles between watering
Special Features: Bark harvested for cork, rugged texture, evergreen foliage, slow and steady refinement