The archetypal oak grows large and spreads wide, with muscular, near-horizontal lower branches that seem to defy gravity. But the group’s 500 species, all native to the Northern Hemisphere, also include upright, pyramidal, and shrubby oaks; in fact, “chaparral” comes from chaparra—Spanish for a dwarf evergreen shrub oak. Oak leaves can be deciduous or evergreen (the latter are called live oaks); lobed, toothed, or smooth edged; but they’re always arranged in an alternate pattern along stems. Some have terrific fall color. All oaks produce inconspicuous flowers followed by acorns, whose single nuts have cuplike caps covered with closely set scales. Some kinds of acorns are edible and sweet, while others are bitter and unpalatable.
Oaks come in two broad categories: white oaks have acorns that mature during the season in which they are produced, and often have leaves with rounded lobes; red and black oaks have acorns that take two seasons to mature, and often have leaves with pointed lobes. Each group can hybridize only within itself.Quercus acutissima
Deciduous tree. Moderate to fast growth to 35–45 ft. (ultimately 50–70 ft.) tall and wide, usually with open, spreading habit. Dark gray bark with red-brown furrows. Shiny dark green, pointed, oblong leaves are 3–7 in. long, with bristle-toothed, slightly wavy edges; they look like chestnut (Castanea) leaves. Foliage is yellowish when new, turns yellow to yellowish brown in fall; may hang on late into winter. Acorns are blunt cylinders to 1 in. long, enclosed for two-thirds of their length in a burlike cap. Prefers well-drained, slightly acid soil but is fairly tolerant of other soils. Good shade or lawn tree.
Evergreen tree. Round headed and densely foliaged; grows to 20–70 ft. tall, often with even greater spread. Smooth dark gray bark is deeply fissured in very old trees. Oval, convex, stiff, leathery dark green leaves, tooth edged and hollylike, 1–3 in. long. Foliage is attractive all year (unless devoured by oak moth caterpillars). Conical, 3/4–1/2-in. acorns are enclosed for one-fourth of their length by a cap with thin, overlapping scales. Has greedy roots; drops almost all its old leaves in early spring. Despite its flaws, this is a handsome and worthwhile shade or street tree. Can be sheared to make a 10–12-ft. hedge. Susceptible to sudden oak death.Quercus berberidifolia
Semievergreen shrub or tree. Native to California chaparral from 300–5,000-ft. elevation. Dense growth to 6–15 ft. tall and wide. Leaves are variable in shape, with wavy edges; may have smooth, toothed, or spiny margins. Medium green on top, gray-green below. Oval acorns to 1 in. long enclosed by up to one-half in knobby cap with spiral pattern. Good unthirsty clipped hedge, background shrub, or informal screen. Has long been confused with Q. dumosa, which is native only near the Southern California coast.Quercus bicolor
Deciduous tree. Slow to moderate growth to 50–60 ft., rarely taller, with equal or greater spread. Bark of trunk and branches flakes off in scales. Shallowly lobed or scalloped leaves are 3–7 in. long, a little more than half as wide, shiny dark green above, silvery white beneath. Fall color is usually yellow but sometimes orange, fiery red, or purple. Oblong to egg-shaped, 1-in. acorns are enclosed by one-third in rounded cap with hairy scales. Tolerates wet soil; also thrives where soil is well drained.Quercus chrysolepis
Handsome, round-headed or somewhat spreading evergreen tree to 20–60 ft. tall and wide. Bark is smooth and whitish when young, checked and gray with age. Oval, 1–2-in.-long leaves may be smooth edged or spiny; shiny medium green above, pale blue or grayish beneath, with thin felting of silvery or golden hairs on undersides when new.
This deciduous tree can reach 60–80 ft. tall and 40–60 ft. wide. Pyramidal when young, round topped in maturity. Gray-brown bark is cracked into irregular plates. Bright green leaves are 3–6 in. long, with pointed, deeply cut lobes; turn scarlet where fall nights are cold. Rounded, 3/4–1-in. acorns are half-covered in a bowl-like cap.Quercus douglasii
This deciduous tree is native to the dry foothills around California’s Central Valley and interior valleys of Southern California. Low branching, wide spreading; to 30–50 ft. tall and 40–70 ft. wide. Light gray bark is shallowly checked in small squares. Shallowly lobed, oval, bluish green leaves are 1 1/2–4 in. long, 3/4–2 in. wide. Attractive fall colors: pastel pink, orange, yellow. Egg-shaped, 3/4–1 1/4-in. acorns with sharply pointed tip and thin, flat cap. Good in dry, hot situations. Immune to sudden oak death.Quercus durata
This evergreen shrub is native to northern Coast Ranges to San Luis Obispo area and to Sierra Nevada foothills, south to San Gabriel Mountains. In the wild is mostly confined to serpentine soil (a kind of nutrient-poor soil). Dense, rounded growth to 10 ft. tall and 8–12 ft. wide. Bare and somewhat leggy to 3–5 ft. above ground, then forms open-branched tiers of foliage. Tough, oval, convex, 3/4–1-in.-long leaves have smooth or prickly edges; dark green above, pale gray beneath, with a dense coating of fine, soft hairs. Acorns are variable: 1/2–1 in. long, often almost cylindrical, half-enclosed in a warty, bowl-shaped cap.Quercus emoryi
This evergreen tree is native from Arizona to Texas and adjacent Mexico. Handsome and rounded, it grows to 50 ft. tall and 40 ft. wide. Leathery dark green, oval, sharply toothed leaves to 2–3 in. long are holly-like but flat; they turn golden and drop just before new growth begins in late spring. Round-tipped, oblong, edible acorns are enclosed by up to one-half in bowl-like cap. Grows well in low desert areas; tolerates a variety of soils. Needs periodic summer soakings.Quercus engelmannii
This evergreen tree is native to Southern California. It has a spreading habit to 40–50 ft. tall, often twice as wide. Thick, leathery, dull bluish green, oval or oblong leaves are wavy surfaced or flat, usually smooth edged. Oval to cylindrical, round-tipped acorns to 1 1/4 in. long are half-enclosed in a warty cap. Tree grows best with monthly deep soakings in warm season, but don’t keep it constantly moist. In its native area, it has the same cherished native status as the more widespread Q. agrifolia. Not susceptible to sudden oak death.Quercus gambellii
This deciduous tree or shrub is native to Nevada, Arizona, and east to Colorado and New Mexico. Slow growth to 15–30 ft. (rarely 50 ft.) tall and half as wide. Often forms colonies from its root system. Thick, ridged trunk bark is light gray to whitish. Leaves are 3–7 in. long, half as wide, with seven to nine deep lobes; dark green above, pale and densely hairy below. Foliage turns yellow, orange, or red in fall. Woolly, egg-shaped or globular, sharp-tipped acorns nearly 1 in. long, half-covered by a knobby cap. Characteristic oak of Arizona’s Oak Creek Canyon and foothills south of Denver. Adaptable to a wide range of soils and moisture levels; grows rapidly into a substantial tree in deep, rich soil.
Deciduous tree native to California, Oregon, Washington, and British Columbia. Slow to moderate growth to 40–90 ft. tall and 30–60 ft. wide, with a rounded crown. Branches are often twisted; bark is gray, scaly, checked. Leathery, 3–6-in.-long, broadly oval leaves with rounded lobes. Foliage is glossy dark green above, rusty or downy beneath; turns reddish brown in fall. Globular, edible acorns to 1 1/4 in. long, bulging from a small, scale-covered cap. Tree casts moderate shade and has a deep, nonaggressive root system. Immune to sudden oak death.Quercus ilex
This evergreen tree is a Mediterranean native. It grows to 30–60 ft. tall and wide, with a dense, rounded head and smooth dark gray bark. Leaves vary in shape and size but are usually oval to lance shaped, 1–3 in. long, with smooth or prickly edges; rich dark green on top, covered with gray or yellow hairs beneath. Egg-shaped to nearly round, 1–1 1/2 -in. acorns are gray brown with darker lines, half-enclosed with a deep cap that tapers to the stem. Tolerates salt air; will grow in constant sea wind but tends to be shrubby there. Inland, growth rate can be fairly fast but varies with soil and water conditions. Good evergreen street or lawn tree where coast live oak (Q. agrifolia) is difficult to maintain, though it lacks that tree’s open grace.Quercus kelloggii
This deciduous tree grows to 30–80 ft. tall and wide, with a short trunk, ascending branches, and a rounded crown. Dark gray, furrowed, checked bark. Handsome foliage: leaves unfold soft pink or dusty rose, mature to dark glossy green, turn yellow or yellow orange in fall. Leaves are 4–10 in. long and 2 1/2–6 in.wide, with deep, sharply tapered lobes ending in bristly points. Oblong or almost conical, 1–1 1/2-in. acorns are enclosed by about half in a bowl-shaped cap. Good moderate-size tree for spring and fall color; attractive winter trunk and branch pattern. Susceptible to sudden oak death.
This deciduous tree is California’s mightiest oak, often reaching 70 ft. or taller, with equal or greater spread. Massive trunk and limbs with thick, distinctly checked gray bark. Straight and erect during its first several decades of growth; more spreading with age. Limbs are often picturesquely twisted; long, drooping outer branches sometimes sweep the ground. Deeply cut, round-lobed leaves are 3–4 in. long and 2–3 in. wide; dark green above, paler beneath. Shiny, 1/2–2 1/2-in. acorns are conical, enclosed by one-third in a warty, bowl-shaped cap.
This deciduous tree has moderate to fairly rapid growth to 50–80 ft. tall and 30–40 ft. wide. Brownish gray bark with shallow ridges and furrows. Pyramidal in youth, with lower branches sweeping downward. If you remove those branches to gain walking space, the limbs above will simply bend into the same position—so wait to remove lower limbs until the tree is mature and has formed an open, rounded top. Glossy dark green leaves are 3–6 in. long, deeply cut into bristle-pointed lobes; in brisk fall weather, leaves turn yellow, red, and finally russet brown. Much of the dead foliage hangs on in winter. Nearly round acorns to 3/4 in. across are enclosed by about a third in a saucer-shaped, fuzzy cap. Less tolerant of dry conditions than most oaks. Develops chlorosis in alkaline soils. Unlike most native Western oaks, it is a fine tree for growing in lawns.
This deciduous tree grows to 50–90 ft. tall and 30–50 ft. wide. Pyramidal in youth, it spreads wider with age. Smooth gray bark. Leaves look more like those of willow (Salix) than those of a typical oak—2 1/2–5 in. long and 1/3–1 in. wide, smooth edged. Foliage turns yellowish before falling; in warmer regions, dead leaves may hang on through winter. Has the most delicate foliage pattern of all the oaks. Spherical, 1/2-in.-wide acorns have a shallow cap enclosing only the end of the nut.Quercus robur
This deciduous tree is native to Europe. It is a fairly fast grower to 50–60 ft. tall and 30 ft. wide, with a rather short trunk and very wide, open head. Dark green leaves have three to seven pairs of rounded lobes. Leaves hold until late fall without much color change. Acorns are to 1 1/2 in. long, varying in shape from oval to oblong, coming to an abrupt point; they are covered by up to one-third in a velvety, bowl-shaped cap. ‘Argenteamarginata’ has white-edged leaves, grows slowly to 20–30 ft.; narrow in youth. ‘Clemons’, a hybrid with Q. macrocarpa, grows about to 50 ft. tall and 40 ft. wide; has a little more cold tolerance than pure English oak. ‘Concordia’ grows about to 25 ft. tall and wide, with golden foliage. ‘Kindred Spirit’, a hybrid between columnar English oak and Q. bicolor, grows to 35 ft. tall and 6 ft. wide, with good disease resistance and tolerance to wet soil and drought. ‘Rosehill’—part English oak, part unknown species—grows to 40 ft. tall and 20 ft. wide, with glossy green, mildew-resistant foliage. ‘Skyrocket’ grows to about 45 ft. tall and 15 ft. wide, and holds its shape well. ‘Skymaster’ becomes a broad pyramid to 50 ft. tall and half as wide. ‘Crimson Spire’, a hybrid with white oak (Q. alba), is another narrowly upright grower (to 45 ft. tall and 15 ft. wide); it has reddish fall color and good mildew resistance.
Q. r. fastigiata, upright English oak, is columnar like Lombardy poplar (Populus nigra ‘Italica’) when young, growing to 50 ft. tall and 15 ft. wide, then maturing to a broad, pyramidal shape. ‘Regal Prince’, similar in height but slightly wider, is a cross between Q. r. fastigiata and an oak from the southeastern U.S.; it’s adaptable and resistant to mildew.Quercus rubra
This deciduous tree is a fast grower to 60–75 ft. tall and 50 ft. wide, with spreading branches and a rounded canopy. Bark becomes quite dark and fissured with age. Leaves are 5–8 in. long, 4–6 in. wide, with three to seven pairs of sharp-pointed lobes. New leaves and leafstalks are red or bright yellow in spring, dark green in summer, turning dark red, ruddy brown, or orange in fall. Acorns are 3/4–1 in. long, shaped like a toy top, enclosed by one-third in a shallow cap; often profuse, creating litter on pavement. Needs fertile soil and regular moisture. High-branching habit and reasonably open shade make it a good tree for big lawns, parks, or broad avenues. Deep roots make it good to garden under. Known host of the fungus that causes sudden oak death.Quercus suber
This evergreen grows to 30–60 ft. tall and wide. Trunk and main limbs are covered with handsome, thick, corky bark (the cork of commerce). Toothed, 3-in., oval leaves are shiny dark green above, gray beneath. Egg-shaped acorns with a short point are 3/4–1/2 in. long, covered by one-third to one-half in a bowl-shaped cap. Good garden shade tree; light-textured foliage contrasts interestingly with the massive, fissured trunk. Needs good drainage. Fairly tolerant of various soils, but foliage may turn yellow in highly alkaline conditions. One of the best oaks for desert areas. Value as a street or park tree diminishes when children find out how easy it is to carve its bark.Quercus vaccinifolia
This evergreen shrub is native to the mountains of Northern California and southern Oregon. Grows to 2–5 ft. tall and at least twice as wide, with sprawling branches. Oblong to egg-shaped, smooth-margined leaves are pointed or round at the tip; shiny gray-green above, gray with sparse golden hairs below. Round to oval acorns to 1/2 in. long have a shallow cap covered in thin, hairy scales. Useful in wild gardens and as an informal hedge.Quercus virginiana
Grows at a moderate to fast rate, eventually reaching 40–80 ft. tall, with a heavy-limbed crown spreading twice as wide. Long-lived; with age, the bark becomes very dark and checked. Smooth-edged, narrowly oval, 1/2–5-in.-long leaves are shiny dark green above and whitish beneath. Oval acorns to 1 in. long, with a sharp spine at tip; enclosed by one-fourth in a bowl-shaped cap with hairy scales. Best in deep, rich, moist soil. In hot interior climates, it’s the most attractive of the evergreen oaks. Best oak for lawn planting in low desert areas.Quercus wislizenii
This evergreen tree is native to the Sierra foothills, eastern side of Coast Ranges, and the interior valleys from southern Oregon to Southern California. Grows to 30–75 ft. tall, often broader than high, with a dense, rounded canopy. Elliptical glossy green leaves have smooth or spiny edges and abruptly pointed tip. Slender, conical, sharp-pointed, 3/4–1 1/2-in. acorns are enclosed by one-fourth to one-half in a flat-scaled cap. Handsome tree for parks and big lawns. Young plants are sparse and angular, offering little hint of their ultimate beauty.
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