Quercus suber, commonly know as the Cork Oak, is from the family of Fagaceae. The cork oak is a dicot, originating from the Mediterranean area. This tree can reach heights of over 65 feet, though in its native environment, it often appears stunted. The leaves are between 2 to 3 inches in length. Under normal conditions, seasonal growth can be between 24 and 36 inches.

The cork oak has many identifiable features. Most noticeable is its jagged and corky bark which can grow to considerable thickness. The bark is light gray in color, with deep furrows of reddish brown. As for the leaves, they are weakly lobed and coarsely toothed while being dark green above and gray below. The leaf margins often curve downward.

The tree itself is either oval, rounded or umbrella like in shape with branches and leaves spreading out an extensive area.


The cork oak is a hardy Evergreen which can survive in the Sunset Zones 5 through 16 and 18 through 23 which is equivalent to the USDA Hardiness Zones 8 through 10.

The flowers are monoecious, which means they have separate female and male flowers. These flowers appearing in spring. The males are slender, yellow-green 2-3 inch catkins, while the females are very small and in clusters of 2 to 4 in leaf axils. The fruit are brown acorns of .5-1.5 inches in length. They mature between fall and winter in prolific numbers. Acorn shape is narrow and oblong, with a loose scaly cap covering approximately 1/2 of the fruit.


The Cork Oak can survive in soils either moist or dry, highly alkaline or acidic. These attributes allow it to be tolerant of droughts and different soil pH. Along with this, the cork oak can survive in various soil types, including clay, loam, and sand. As for light requirements, full sun to partial shade is suitable. Other adaptations include a resistance to verticillium and fire.

Here are some interesting facts about the cork oak:
• The largest commercial growth of Cork Oak is in Portugal.
• The cork used in domestic products, such as wine bottle stoppers and bulletin boards, are produced from the bark of this tree.
• The Cork Oak is most widely cultivated in Spain, Portugal, Algeria, Morocco, France, Italy, and Tunisia.
• The European cork industry produces around 340,000 tones or cork a year, a value of €1.5 billion.

Back to Cork Oak Main Page