The English oak is native to Europe and can be a very imposing, majestic tree at maturity. In cultivation in the U.S., it is unlikely to reach the 75 to 100 feet scale often seen in Europe. Its wood has been used to build ships, houses, and furniture, as well as casks for maturing wines and spirits. The fruit of the oak tree is the acorn, which usually appears in September and is very popular with squirrels. The English oak is a member of the white oak group with the characteristic rounded, lobed leaves and annual acorn production.

The genus Quercus includes more than 600 species of the oak tree, of which 90 are native to North America; the Chicago Botanic Garden's collection contains more than 60 varieties and over 1,000 individual trees. Twenty oak species are native to Illinois.

Oaks are slow growing, long lived, hard wood trees that produce fruit we all know as acorns. Within the white oak group, acorns mature annually; in the red oak group, acorns take two years to mature (biennial). Oaks are often imposing shade trees at maturity and provide habitat and food for a variety of wildlife.