Quercus chrysolepis (Canyon Live Oak)

Magnificent and exceptionally long-lived, Quercus chrysolepis (Canyon Live Oak) is a highly variable evergreen oak that may grow as a large shrub or an impressive tree, depending on site conditions. On exposed mountain slopes and ridgetops, it often develops as a dense, spreading shrub or thicket, while in sheltered, moist canyons it can form a substantial tree. Open-grown specimens develop broad, dense crowns that may sweep nearly to the ground, while trees in closed stands tend to carry a narrower crown higher on the trunk.

The bark ranges from smooth and flaky on smaller stems to deeply furrowed on older trunks. Thick, leathery, oblong leaves, up to 4 in. long (10 cm), vary from blue-green to glossy dark green. Young trees often bear spiny-edged leaves, while older trees tend to develop smoother margins, although both leaf types may occur on the same plant. Male flowers are borne in catkins, while female flowers occur singly or in sparsely flowered spikes. The light chestnut-brown, ellipsoidal acorns provide an important food source for birds and small mammals.

Canyon Live Oak is remarkably well adapted to dry conditions. Its deep, extensive root system can tap reliable moisture sources during prolonged summer drought, helping mature trees persist on steep, rocky, and exposed sites. This root system also makes the species valuable for stabilizing difficult slopes. With its evergreen foliage, broad crown, and sculptural form, Canyon Live Oak is one of the most distinctive western oaks and can make a striking shade or specimen tree where space allows.

The oak genus includes many beloved trees, such as Live Oak, White Oak, Red Oak, Blue Oak, Bur Oak, and Pin Oak.

Oaks support an exceptionally wide range of butterfly and moth larvae. Species associated with oaks include the Banded Hairstreak (Satyrium calanus), Edward’s Hairstreak (Satyrium edwardsii), Gray Hairstreak (Strymon melinus), White-M Hairstreak (Parrhasius m-album), Horace’s Duskywing (Erynnis horatius), and Juvenal’s Duskywing (Erynnis juvenalis). Its acorns also provide valuable food for wildlife, including birds and mammals.

• Grows up to 30-80 ft. tall (9-24 m) and 30-60 ft. wide (9-18 m), though exposed plants may remain shrubby.
• A full sun to part shade lover, this tree is easily grown in very acidic to slightly alkaline, well-drained loam, sand, or clay soils. Once established, it is strongly drought tolerant and also moderately tolerant of salt spray.
• Well suited as a specimen tree, shade tree, or for slope stabilization and naturalistic western landscapes.
• May be affected by sudden oak death, crown rot, mistletoe, Armillaria, invasive shot hole borer, goldspotted oak borer, aphids, and caterpillars.
• Propagate by seed. Sow fresh acorns promptly, either outdoors or in deep containers that can accommodate the developing taproot.
• Toxic to horses if significant quantities of leaves or acorns are consumed.
• Native to Oregon, California, Nevada, Arizona, and Mexico.