The black oak (Quercus velutina) grows throughout the eastern U.S. with the exception of most of Florida, along the Gulf Coast and northern sections of New England. The species takes its name from its almost black bark and is a long-lived oak species. Black oaks make excellent shade trees and their wood goes into products like fence posts, furniture, barrels and railroad ties.
The typical black oak, according to the Ohio Department of Natural Resources website, grows to 60 feet high and is 60 feet wide at its top. Black oak leaves are as long as 10 inches and have from seven to nine lobes with bristles on their ends. The green leaves change to yellow or red in the fall, giving the tree an attractive autumn look.
The flowers of the black oak tree include both male and female types, with the males able to fertilize the small female flowers in the middle of spring. The male flowers, called catkins, are a yellow-green color and droop down from the branches in the spring. The female flowers are a combination of red and green and exist on shortened spikes. Both sexes of flowers are in full bloom by May in most parts of the tree’s range.
The result of the female flower’s pollination eventually is an acorn that takes two full growing seasons to develop. By the acorn’s second summer it is getting much larger and it will ripen by autumn before falling off the tree. The acorn is a half inch to three quarters of an inch long by then, with a bowl-like cap. Animals such as deer, wild turkeys, chipmunks and crows will eat them but humans find the taste extremely bitter.
Black oaks grow best in full sun and the tree will flourish if planted in well-draining, moist ground that is acidic in nature. The species is tough to transplant successfully because it does not do well after being disturbed from its original growing site. If you must transplant a black oak, do so while it is relatively young and small.
In a forest setting, the black oak is a companion tree to species such as red maple, hickories and black walnuts. Another oak that can grow alongside it is the red oak, which closely resembles the black oak, but with larger acorns and more lobes on its leaves. The bark of the black oak is smooth and gray on the young specimens but full of deep furrows on the older trees and quite rough to the touch. The inner layer of bark is an orange-yellow combination, giving the tree one of its nicknames—yellow oak.