Blackjack Oak: A Tough but Ugly Tree for Problem Sites
Blackjack oak (Quercus marilandica) is a medium-sized oak tree native to central and eastern USA and all areas of NC except the higher elevations. It is often an understory tree that grows in the shadow of taller oaks such as the post, scarlet and red oak. It has a rounded, irregular crown; distinctive bark; and a tendency to retain dead branches on the middle to lower part of the trunk.
Blackjack oak can grow in poor, thin, dry, rocky or sandy soils where few other woody plants can thrive. It is sometimes considered a “tough but ugly” tree, but also underappreciated for its ecological value. It provides food and shelter for wildlife, such as squirrels, deer, turkeys and songbirds. It also supports pollinators with its catkin-like flowers that appear in May.
Blackjack oak can reach heights of 50 feet or more, but usually stays around 20 to 40 feet tall and wide. The leaves are dark green and glossy above, pubescent underneath, and often remain attached to the twigs through the winter after turning colors from red to brown in the fall. The leaves are 7â20 centimeters (3â8 inches) long and broad, and typically flare from a tapered base to a broad three-lobed bell shape with only shallow indentations. The acorns are small, 12â20 millimeters ( 1â2 â 3â4 in) long and 10â18 mm ( 3â8 â 3â4 in) broad; like those of other red oaks, they take 18 months to mature.
If you are looking for a tree that can grow in problem sites with poor soil and provide shade and wildlife benefits, then blackjack oak might be a good choice. However, be aware that it does not have the graceful form of many oaks, and it might need some pruning to remove dead branches and improve its appearance. Blackjack oak is also susceptible to some pests and diseases, such as oak wilt, anthracnose, canker and borers. Blackjack oak is not commonly found in nurseries, so you might need to look for a specialized shop or online source to get one.
Blackjack oak is a tree that can adapt to harsh conditions and survive in places where other trees cannot. It is a valuable member of the oak family, and deserves more recognition and appreciation for its role in the ecosystem. Here are some more facts and tips about blackjack oak:
- Blackjack oak is also known as barren oak, black oak, jack oak and scrub oak. The name “blackjack” comes from its dark bark and wood, which were used for making fence posts and railroad ties.
- Blackjack oak is one of the few oaks that can grow in alkaline soils. It can also tolerate drought, fire, salt spray and air pollution. However, it prefers acidic to neutral soils that are dry to medium well-drained.
- Blackjack oak is a slow-growing tree that can live for more than 200 years. It has a deep taproot that helps it anchor in the soil and access water and nutrients. It also has lateral roots that spread horizontally and form suckers.
- Blackjack oak is a good tree for wildlife habitat and erosion control. It provides food for many animals, such as acorn weevils, woodpeckers, blue jays, nuthatches, mice, chipmunks, rabbits, raccoons and bears. It also offers shelter and nesting sites for birds and mammals. It can form dense thickets that protect the soil from wind and water erosion.
- Blackjack oak is not a good tree for lumber or firewood. Its wood is hard, heavy, coarse-grained and brittle. It splits easily and warps when dried. It also has a high moisture content and low heat value. It is mainly used for charcoal, pulpwood and fuelwood .
If you have a blackjack oak in your landscape or garden, you can enjoy its beauty and benefits throughout the year. You can admire its distinctive leaves that change color in the fall and persist in the winter. You can watch the wildlife that visit and feed on its acorns and flowers. You can also appreciate its resilience and toughness that allow it to grow in challenging environments.