
Valley Oak
The Valley Oak grows into the largest of North American oaks. It ranges over the hot interior valleys of California
where there is a water table within reach of the roots. Valley Oaks grow quickly, reaching 20 feet in 5 years, and 40
feet in 10 years, and up to 60 feet in 20 years. Mature specimens may attain an age of up to 600 years. Its thick,
ridged bark is characteristic and evokes alligator hide. The sturdy trunk of the Valley oak may exceed two to three
meters in diameter and its stature may approach 100 feet in height.
The branches have an irregular, spreading and arching appearance that produce a profound leafless silhouette in the
clear winter sky. During Autumn leaves turn a yellow to light orange color but become brown during mid to late fall. In
advancing age the branches assume a drooping characteristic. Its pewter-colored rippled bark adds to the attractive
aesthetic of this species. Typically, leaves are five to ten centimeters in length and are roundly and deeply lobed. The
leaf width is approximately one half its length. Each leaf is matte green with an underneath pale green appearance;
moreover, the leaf is covered with abundant soft fuzz, yielding an almost velvety feeling. When a fresh leaf is rubbed
or broken, an aromatic scent is exuded, evoking a forest odor. The wood is a dull brown approaching yellow. Over
most of the range, acorns fall in October. A variety of mammals and birds eat them, including the Acorn Woodpecker,
Western Scrub Jay, Yellow-billed Magpie, and California ground squirrel. Like many oaks, Valley Oaks can tolerate
wild fires. Although smaller individuals may be top-killed, most resprout from the root crown. Valley oak tolerates cool
wet winters and hot dry summers, but requires abundant water. It is most abundant in rich deep soils of valley floors
below 600 meters in elevation but can also be found at elevations up to 5,600 ft.. Valley oak is found in dense riparian
forests, open foothill woodlands and valley savannas. Commonly associated trees are Coast live oak, Interior live
oak, Blue oak, Black walnut, California Sycamore and Ghost pine. The Valley oak is widely distributed in the
California Central Valley and many smaller valleys such as the San Fernando Valley.
Because of its eventual size, it may not be appropriate for the average residential garden. Best not to provide
irrigation within 30 feet of established valley oaks. They'll often absorb too much water, causing limbs to break off.