50 to 60 ft.
35 to 45 ft.
eastern North America
USDA zones 2-8
hardy to 6,500 ft.
Bur oak is a very large, stately, drought tolerant shade tree. It is a slow-growing member of the white oak family with a broadly rounded crown at maturity. It has medium green, deeply lobed leaves that turn yellow, gold, and brown in the fall.
The bark of the main trunk and branches is corky and deeply furrowed, while the twigs are almost winged with deep ridges of bark. Large (up to 1 1/2 inches), fringed acorns are produced in fall.
Bur oak is more tolerant of alkaline soils than many oaks, and very drought tolerant once established. It may retain some brown leaves during winter when young. It is an excellent choice for a large, long-lived, drought-tolerant shade tree.
At the Xeriscape Demonstration Garden, there are three bur oaks. They have been slow to establish. Over time, the oldest two have grown into attractive, low-water trees.
One of their best qualities is that they leaf out late in spring, often avoiding spring storm damage. Bur oak may may be best suited to areas larger than most homeowners' yards. However, it still deserves consideration for use in the Colorado Springs area where a large tree is desired.
At maturity these are beautiful, majestic, long-lived trees.
Prune out dead or damaged branches as needed. Prune when young to achieve desired shape.