Pin Oak (Quercus palustris) — identification, habitat & look-alikes

Pin oak is one of the most widely planted oaks in the eastern and central US, easy to spot by its tidy pyramid shape: upper branches angle up, middle ones stick straight out, and the lowest ones droop. Its deeply cut leaves often hang on, brown and dry, through winter on young trees. In the wild it grows in wet, clay-soil bottomlands.

Appearance

Growth form: A medium-sized deciduous tree, usually 60–70 ft (18–22 m) tall with a trunk up to about 3 ft (1 m) across.
Leaves: 2–6 in (5–16 cm) long, with 5–7 lobes separated by deep, U-shaped notches that reach close to the midrib. The underside has small tufts of brownish hair where the veins meet. Fall color ranges from bronze to russet red.
Fruit: Small, nearly round acorns about 0.4–0.6 in (10–16 mm) long, often finely striped, with a thin, saucer-shaped cap covering about a quarter of the nut. They take about 18 months to ripen, so they mature in the second fall.

Look-alikes

Scarlet oakQuercus coccinea

Scarlet oak's leaf notches are C-shaped rather than U-shaped, and its leaves have no hair tufts underneath. Its acorn cap is a deep cup covering a third to half of the nut, compared with pin oak's shallow saucer. In fall scarlet oak turns bright scarlet, while pin oak is usually more bronze.

Why they get mixed upBoth have very deeply cut leaves, and older pin oaks lose their tidy shape and look much like scarlet oaks.

Northern red oakQuercus rubra

Northern red oak leaves are larger (5–10 in) with 7–11 shallower lobes, and its acorns are bigger, about 0.5–1.25 in long.

Why they get mixed upBoth are common red oaks with bristle-tipped lobes.

Where it lives

Typical habitats: Floodplains
River bottoms
Streets and parks
Range: Native to the eastern and central US, from Massachusetts and southern Michigan west to Kansas and Oklahoma and south to Tennessee and Georgia; also southern Ontario.
Preferred conditions: Poorly drained, often acidic clay soils from sea level to about 1,150 ft (350 m). It handles flooding well while dormant but much less during the growing season.

Growing it

Care: Hardy to USDA zone 4. It transplants easily thanks to shallow, fibrous roots and grows fast, but needs acidic soil; on alkaline soils the leaves turn yellow (iron chlorosis), a common problem in cities. Its drooping lower branches can block sidewalks and streets.

Name and classification

About the name: The species name palustris means 'of the marsh,' for its wet habitat. The common name may come from its many short, slender twigs or from its wood once being used for pins in building. Northern pin oak (Quercus ellipsoidalis) is a different species.
Varieties and forms: Many nursery selections exist, including narrow, upright forms for tight street plantings and forms whose lower branches grow upswept instead of drooping.