Quercus berberidifolia (scrub oak) is a native species to the scrubby hills of California. It is a common member of the chaparral ecosystem with the word chaparral being derived from the Spanish word for scrub oak, chaparro. These oaks share a heritage with California culture, not only biologically but socially. Their vast contribution to the native tribes of the Southwest as food, fuel, medicines, structures and weapons provided a natural resource and because of that Native Americans have historically played a major role in the conservation of oak landscapes.

Scrub oaks are prolific, drought tolerant and have the unique ability to resprout after wildfire, making them a valuable member of the chaparral. They might be considered the “default” oak of the California chaparral, but their distinctive biology makes them a perfect fit for areas such as the rocky soils of the San Gabriel mountains, along with the Sierra Nevada foothills, the Tehachapi Mountains and the dry, interior climates of coastal Southwestern California.

Scrub oaks are a smaller, shrubbier version of the larger, more familiar oaks. Ecosystems that have extended dry periods favor shrubs. It’s ability to resprout after fire is a trait that allows scrub oaks to survive this harsh environment. These woody foundations create a habitat for other plants that blend together to make up an understory flora necessary for sustainable oak woodlands.

The Value of Understory Plantings

Native species have a special relationship with one another because each species enhances the viability of the other to survive and adds the most benefit to the habitat it supports. This unique relationship is sometimes referred to as “companion plantings”. In the oak woodlands, there are many companion plantings that comprise the understory structure of this landscape. Plants found thriving underneath oaks are making a contribution not only to the oak trees, but also to the surrounding biome.

Some companion understory plantings include Californias' aromatic sages, rustic buckwheat (photo at right) and wild currants (photo at left, just to name a few. These eye pleasers have several roles, but their main role as companion plants is to provide shelter to the younger, developing plants and food resources for the diverse populations of insects, birds and mammals that inhabit the oak woodland forest.

Leaves and Flowers

Scrub oaks are an evergreen or semi-evergreen dense shrub up to 15 feet in height, with holly-like leaves that are spinytoothed and painful to grasp. The 1/2 to 1 1/2 inch long leaf is shiny green above and smooth or finely fuzzy beneath, with a leathery, stiff texture. Leaf shape is usually oblong to elliptical.

All oaks have a fuzzy (hairy) underside to the leaf to accommodate dry conditions by giving the plant extra surface area for moisture to collect and providing protection from scalding, sunny mesas. Those fuzzy hairs, called trichome hairs, will determine what species of oak is present when scrub oaks hybridize. Careful counting of trichome hairs gives biologists an accurate assessment of species regeneration within the chaparral. Flowers are typical for oaks; monoecious with male flowers in drooping 1 inch long yellow-green catkins.

Fruits

Acorns are produced either singularly or in pairs during summer to early fall and are egg-shaped or pointed. Usually 1/2 to1inch long they have a warty cap that covers about 1/3 of the nut.

Acorns ripen during one growing season with the nut changing colors; transitioning from green to light brown, then eventually maturing to a rich espresso brown hue. 

Protect & Enjoy

Protecting our native trees requires our active partnership and contribution to the common goal of resource management. Oak, sycamore, and bay trees hold a unique place in our local ecosystem and provide habitat for 81 species of resident and migratory birds.

Urbanization continues to present a challenge within the sustainable capability of the ecosystem. Open spaces, clean air and homes for wildlife are worth protecting, but will demand support for the native trees existence in the local landscape.

Trees are living resources and assure healthy living habitats for interconnected flora and fauna, and the people that live within these habitats. To ensure that our trees will survive and thrive, please protect them by following these suggestions:

• Do not injure the trunk with objects.
• Keep all machines and weed whips away from tree trunks.
• Practice conservative pruning.
• Do not over water.