English Oak
COMMON NAME: English Oak, Truffle Oak, Pedunculate Oak
SCIENTIFIC NAME: Quercus robur
FAMILY: Fagaceae
This tree in Colorado: Several English Oaks in Europe are believed to be more than 1,000 years old. It is a large shade tree at maturity with a massive trunk and branches. It is an underused tree along the Front Range mainly due to its lack of fall color. There are several fine examples of mature English Oaks at Fairmount Cemetery in Denver.
Hardiness: Zones 4 to 8
Growth habit: Large, open headed shade tree with an initially rounded or pyramidal crown becoming broad and rounded at maturity.
Foliage: Alternate, simple, 2 to 5” long and ¾” to 2-1/2” wide, with 6 to 14 shallow, rounded lobes. English Oak leaves are thick and glossy. They are dark green to almost blue-green above with a pale blue-green underside in the summer. They sometimes drop when still green but usually turn yellow/brown late in the fall and hang on into winter.
Flowers Males produce a yellow-green catkin in the spring.
Fruit: Acorns are 1/2” wide and 1” long. They occur singly or in clusters of up to five and ripen the first year (English oaks are in the White oak group). They are a shiny brown color, usually enclosed about 1/3 by their cap.
Bark: Dark green or brown and smooth when young, changing to brown and then a deeply furrowed dark gray at maturity.
Cultivars: More than 100 cultivars have been introduced. The most common is ‘Fastigiata,’ or Columnar English Oak which grows only 15’ wide by 50-60’ tall.
Landscape value: This tree adapts well to most soil types and is relatively pest free. Plant in full sun, allow plenty of space for growth, and prune for structure often when young. English Oaks provide dense summer shade. When considering placement in the landscape, remember that the brown leaves often persist through the winter creating an ice/snow shadow on the north side of the tree. Don’t plant on the south side of a building, street, driveway or parking lot. This tree is considered drought tolerant once established but is not as xeric as Bur or Gambel oak.
Information sources: Michael Dirr, Manual of Woody Landscape Plants (University of Georgia, 1990)University of Connecticut Plant Database
Photo by Historic UK