White Oak Tree (Quercus alba)

From the Tree & Landscape Board

The state tree of Maryland is the White Oak (Quercus alba) and is native to much of the eastern half of the United States. The oak genus (Quercus) has over 500 species along with many natural hybrids. White Oak leaves are generally 2 to 4 inches long with 7 to 10 shallow lobes but because of the existence of natural hybrids it may be difficult to identify some oaks in the field. The tree can reach 150’ tall but typically tops out between 80’ and 100’. If not crowded by other trees it will form a rounded crown that can be 80’ across. The life span of a typical White Oak ranges from 200-400 years.

It flowers in the spring and the acorns that are produced will drop in the autumn of the same year. Acorns of the White Oak will germinate almost immediately so if you find a squirrel’s cache of acorns in the winter or spring that means those acorns are not from a White Oak. Yes, squirrels can tell the difference between White Oaks and other oaks! White Oak acorns are less bitter than those of other species of oaks. Wildlife will preferentially browse on White Oak acorns even if acorns from other oaks are available. It is a good idea to leave the leaves under your White Oak as the humus layer that the leaves produce is important for good seedling establishment. Seedlings and young trees have a taproot which can make it difficult to transplant. As the small tree matures that taproot is eventually replaced by a fibrous root system.

In addition to providing food for White-tailed deer and Wild Turkey the White Oak also provides habitat for nesting birds, squirrels, and our native tree roosting bats along with innumerable insects and other invertebrates. Oaks are one of the greatest supporters of insect diversity and abundance and have a very important function in terrestrial food webs. This genus supports more moths and butterflies than any other native species.

The wood of White Oaks has a unique characteristic that being naturally waterproof and resistant to decay. This is due to parenchyma cells which fill up with a structure called tyloses and become non-porous. Tyloses extend inside the heartwood and form a barrier to bacteria and fungi. Other oaks do not have this cell structure. This property in White Oak is why it was an important material in ship building in the past and even today in the marine industry. Also this property still makes White Oak the prime source for making whiskey and wine barrels.

Not all of the White Oak’s attributes are found above ground. A newly identified native truffle fungus, Tuber cumberlandense (there’s no common name for this), grows symbiotically on the roots of White Oaks. It may prove useful in the future for use in truffle orchards.

Because the White Oak is such an important species a group of foresters employed in industry, government, and researchers have started a program called the “White Oak Initiative”. This organization is concerned with regeneration and management of the species.

In summary the White Oak tree has many beneficial characteristics and uses like food for wildlife, lumber for the marine and whiskey industry, and shade for our streets and parks. Finally, the largest known specimen had a circumference of thirty-two feet and was located right here in Maryland at the Wye Oak State Park. It was destroyed in a storm June 6, 2002.

You can learn more about the White Oak Tree here:

https://www.srs.fs.usda.gov/pubs/misc/ag_654/volume_2/quercus/alba.htm

https://plants.ces.ncsu.edu/plants/quercus-alba/

https://extension.umd.edu/resource/white-oak/

Need tree or gardening help or advice?

Reach out to the City’s Tree and Landscape Board or the Committee for a Better Environment for tips, tricks and ways to help grow your trees and yard.

To help residents, they’ve produced several brochures to help on landscape-related topics for City residents including:

  • How to Grow a Healthy Lawn
  • Grass Clippings - Let ’Em Lay!
  • How to Prune Trees
  • How to Plant Trees
  • From Garbage to Garden: It’s Compost Time!
  • How to Control Bamboo