Quercus imbricaria aka Shingle Oak

Shingle oak, Quercus imbricaria, is a deciduous tree in the beech family, Fagaceae. It grows wild across the central and eastern United States. Its range runs from Pennsylvania south to Georgia and west to Wisconsin, eastern Kansas and Arkansas. In the wild it favours well-drained uplands and turns up less often beside lowland streams. Early settlers split its wood into roof shingles, which gave the tree its common name. Gardeners also call it laurel oak or small-leaved oak.

In gardens it usually reaches 50 to 75 feet (15 to 23 metres) tall. Its spread can match or exceed its height. Some sources give heights up to 100 feet (30 metres), while UK figures suggest a smaller tree of around 40 to 65 feet (12 to 20 metres). Young trees have a pyramidal outline. With age the crown opens into a broad, rounded dome. Upper branches point upward, while lower ones spread or droop much like those of pin oak.

The leaves set this oak apart from most others. They are simple, alternate and unlobed, 3 to 6 inches long, with a bristle at the tip. The upper surface is a glossy dark green, and the underside is paler and sometimes hairy. New leaves open reddish in spring. In autumn they turn yellow-brown to russet, and many dead leaves cling to the branches into winter. The bark is grey-brown with shallow ridges and furrows, and the inner bark is pinkish. Twigs are slender, brown and smooth, with pointed reddish buds.

The tree carries male and female flowers on the same plant in spring, as the leaves expand. Yellow-green male catkins hang in loose clusters, while the female flowers sit near the shoot tips. Wind carries the pollen. The small, rounded acorns are about half an inch long. A thin scaly cup covers roughly a third of each nut. The acorns take two years to ripen and fall in autumn.

Shingle oak likes full sun but accepts partial shade. It does best in deep, fertile, moist but well-drained acid soil. It still copes with clay, sand, drier ground and city conditions. It is hardy to USDA zone 4 and rates H6 in the UK. Severe winters can kill some twigs. Growth is slow, but the tree transplants more easily than many oaks. Use it as a shade, street or specimen tree in large lawns and parks. It also tolerates clipping, so it can form a tall hedge or screen. Wildlife value is high. Birds and mammals eat the acorns, and many moths and butterflies, including several hairstreaks, feed on the leaves as caterpillars.

The tree has fairly good pest resistance. Scale, borers, caterpillars, aphids, leaf miners and gall wasps can still attack it. Oak wilt, powdery mildew and honey fungus are possible diseases. Insect and mite galls are common but do little harm. Raw acorns contain tannins and are mildly poisonous to people, pets and horses. People can eat the acorns after leaching or boiling out the tannins, then grind them into flour.