Oak, Bur

This massive Texas native grows best in the deep limestone soils of riverbanks and valleys, and prefers to grow in the open, away from forest canopy, but will adapt to many different environments. Bur Oak is deciduous, with a rounded, majestic form, reaching a height and spread of 60 – 80 feet.

Bur Oak is a shade tree of notable strength. It is fast growing and long lived, sometimes exceeding 200-300 years of age. It is resistant to air pollution and heat stress, tolerates a variety of moisture and soil conditions, and is even fire-resistant. It has significant drought resistance by virtue of a long taproot, but this also makes it hard to transplant. It prefers full sun, and casts deep shade.

The LEAVES are variable in shape, with 5-9 lobes. Usually, the top portion of the leaf is wider & has shallower lobes, while the bottom portion is narrower with deeper lobes. The very large leaves are simple and alternate, with an entire margin, and are often 6-12” in length or longer.

The FLOWERS of Bur Oak are insignificant drab brown catkins 4-6 inches long that appear from April to May. The very large distinctive ACORNS – the largest of any North American oak – can be as large as 2 inches wide and long, and have a cap that extends about half way down and is fringed.

The somewhat rugged BARK is a medium gray.

Although heavy nut crops are borne only every few years, the Bur Oak acorns are an important WILDLIFE food, a favorite of wood ducks, wild turkeys, whitetail deer, rabbits, mice and squirrels. Black Bears have been known to tear off branches to get the bark. Bur Oak is heavily browsed by cattle in some area and other wildlife, such as deer and porcupine that eat the leaves, twigs and bark.