The Queen of the Valley
“Faith sees a beautiful blossom in a bulb, a lovely garden in a seed,
and a giant oak in an acorn.”
~William Arthur Ward
No matter where you travel, you always know you are home when the oak-studded grassy landscapes of the Central Coast come into view. Nothing looks quite the same as these iconic rural California savannas covering the inland valleys and hills, with swaths of colorful wildflowers in the spring and bright green grasses that turn a tawny brittle brown in the fall. The term “savanna” refers to broad expanses where scattered trees are widely-spaced and grasses grow easily underneath and between them. And the reigning queen of the oak savanna is our own majestic Valley Oak.
The Valley Oak (Quercus lobata) is the most common tree in the savanna, and the largest of all the oaks, often living 600 years and reaching a height of 100 feet. Unlike the Coast Live Oak, they have a more upright stature with deeply checkered alligator bark and thin, lobed leaves that are shed in the fall, leaving their gnarled and massive trunks, branches and limbs darkly silhouetted against the winter sky.
It’s hard to imagine that oak trees are in any danger of being lost, but actually Valley Oaks are “endemic” to California, meaning they do not grow naturally anywhere else in the world. These particular oaks need a source of moisture located by their 50- to 60-foot long tap roots, so only grow in the rich soil of bottom lands and near creeks and springs, also known as prime farmland. More than 75 percent of California oak woodland and oak savanna ecosystems are grazed by cattle and sheep, eating leaves, acorns, seedlings, and saplings. Residential development has been particularly devastating for Valley Oaks, so several agencies (www.Californiaoaks.org) are now involved with helping towns and ranchers learn to conserve, restore and manage our unique oak populations.
There are certain perks that go along with being a queen, and the Valley Oak has the distinction of being a “keystone” species: a plant or animal that plays a unique and crucial role in the way an ecosystem functions. Without keystone species, the ecosystem would be dramatically different or cease to exist altogether. The number of mammals, reptiles, birds, fungi and insects that depend upon the Valley Oak is staggering: studies show that they provide more food and shelter than any other oak.
If the Valley Oak is a queen, then her acorns are the tiny jewels she drapes across her leafy canopy. Wrapped in an elongated tough outer coat with their jaunty caps, the meaty nut inside has been a vital food source for animals and Native Americans for centuries. A single mule deer can eat up to 300 acorns per day when acorns ripen in the fall, just when they need to put on fat.
It’s hard to talk about oaks without mentioning the multitude of birds who are active in and around them. By focusing on just an individual tree for a few minutes, one might see large gregarious groups of acorn woodpeckers darting in and out on their way to stash their tasty acorns in a storage, or “granary” tree. Twiggy nests might be seen on tall branches or in cavities on limbs, along with clumps of parasitic mistletoe which has a unique wildlife value all its own: it is the only caterpillar food plant for the Great Purple Hairstreak, a tiny red and green butterfly with an orange abdomen.
And this queen’s impressive reign doesn’t end where the trunk meets the ground, but continues downward in a vast network of leaves, twigs, and acorns layered between the rich soil. Home to a vital community of insects, amphibians, decomposers and fungi, oak leaf litter is a crucial component of the ecosystem.
Oaks need an undisturbed understory and should not have paving or trenching between their trucks and drip lines. Their root zone is fragile, and compacted soil from foot traffic or parked cars can lead to problems. Mature oaks do not need supplemental water, so only using native plants under oaks is the best way to landscape.
Many people shy away from planting oaks, thinking they are too slow-growing or take up too much space, but when you think of the enormous ecosystem that you will be building and the prospect of having it grow and thrive for centuries to come, it makes it all worthwhile.

