Quercus austrina aka Bastard White Oak

Quercus austrina, or bluff oak, is a deciduous tree in the beech family. It comes from the southeastern United States. Its range runs from North Carolina to Florida and Mississippi. Wild trees grow beside streams and on river bluffs. They favor rich soils that drain well. Some local populations face decline. This oak grows at a moderate rate. Garden trees reach 40–60 feet [12.2–18.3 metres] tall. Their crowns spread 35–50 feet [10.7–15.2 metres] wide. The open crown forms an oval or rounded shape.

The trunk often stays straight through the crown. Well-spaced branches grow upward or outward and resist breakage. Pale gray bark has scales and broad ridges. Dark brown twigs bear raised, pale, corky lenticels. The pointed brown buds have fine hairs. Simple leaves grow alternately along the stems and have pinnate veins. Their edges have shallow, rounded lobes or gentle waves. Leaf size varies between the source accounts. Some report blades reaching eight inches long. Young leaves have hairs, which disappear as they mature. Leaves range from green to gray-green, with paler undersides. Fall foliage can turn copper, orange, or yellow. One Florida account also notes leaves dropping without color change.

Small flowers appear in spring and draw little notice. Male flowers form yellow-brown catkins. Brown acorns grow alone or in pairs. Each nut has a scaly cup around its upper portion. The cup covers about one-third to one-half of the nut. Acorns mature within one year and ripen in fall. Squirrels and other mammals eat them. The tree also supports butterflies and moth caterpillars.

Grow bluff oak in full sun and well-drained, acidic soil. It accepts clay, loam, and sand. It tolerates drought well and can withstand brief floods. It suits USDA zones 8a–9b but does not tolerate salt. Use it for shade in lawns, parks, or natural areas. It also suits streets and parking areas with ample crown space. Its branches need little pruning for road clearance. Fallen leaves and acorns create litter. Growers can raise new trees from seed.

Pests and diseases seldom cause serious damage, though several can occur. These include oak wilt, anthracnose, cankers, and leaf spots. Powdery mildew and oak leaf blister can also affect it. Scales, aphids, leaf miners, and caterpillars may feed on it. High soil pH can cause iron deficiency and yellow leaves. Acorns contain toxic compounds and can cause digestive illness or blockage. They become edible only after treatment removes their tannins.