Quercus stellata aka Post Oak

Quercus stellata, or post oak, is a deciduous tree. It belongs to the beech family and white oak group. Its native range spans the central and eastern United States. It grows from Massachusetts south to Florida and west to Texas. It often grows on dry, rocky slopes with poor soil. The name post oak reflects its use for fence posts.

Garden trees reach about 35–50 feet [10.7–15.2 metres] tall and wide. RHS gives smaller sizes, reaching 39 feet [12 metres] tall. Its listed spread reaches 26 feet [8 metres]. Other sources report heights of 65 feet [20 metres]. The tree grows slowly and forms a dense, broad crown. Its branches may twist and bend with age. Young bark has scales; older bark forms rough, grey-brown ridges. Fine, short hairs cover the pale brown young shoots.

The leaves grow in an alternate pattern along the twigs. They feel thick and tough, with rounded, deep lobes. The large middle lobes often give leaves a cross shape. Some trees lack this shape, so leaf form alone can mislead. Star-shaped hairs cover the pale undersides and young twigs. Fall leaves turn brown, yellow, or dark gold and bronze. Some leaves stay on the tree through winter. Male flowers hang in yellow-green catkins, with bloom reported in April. Small female flowers grow near twig tips. Brown acorns ripen each fall, from September through November. Their scaly cups cover about a third of each nut.

Post oak grows best in full sun and well-drained soil. It accepts several soil types and prefers acid to neutral conditions. It tolerates drought, dry ground, and shallow, rocky soil. RHS also recommends soil that holds moisture without staying waterlogged. Chicago Botanic Garden lists USDA zones 5–9 for the species. RHS rates its UK hardiness as H5. It suits large lawns, parks, streets, and sites left more natural. Birds and butterflies visit it, and its acorns feed wildlife. Builders use its wood for posts, beams, and railway ties.

Post oak needs little upkeep, though pests and diseases can occur. Oak wilt and chestnut blight can harm it. Other risks include mildew, honey fungus, aphids, and gall wasps. Acorns are edible only after treatment removes their tannins. Raw acorns and young leaves can cause gut pain and illness. Dogs can also suffer harm from eating the plant.