Information on Live Oak and Pine Trees

Pine branches provide shade.

Live oak and pine trees are two different species of trees that sometimes thrive in the same setting. Oak trees belong to the quercus genus. They bear acorns and have hard wood. Pines are conifers, or cone-bearing trees. They belong to the pinus genus. California live oak (quercus agrifolia) is native to the foothills and valleys of Southern California. It survives drought and rocky or sandy conditions. Native coulter and radiata pines also survive in the arid, fast-draining soils of the Southwest.

Live Oaks

California live oaks thrive in dry conditions.

California live oak, also called coast live oak, grows in the coastal and valley foothills of Southern California. These evergreen trees can reach 75 feet in height and spread nearly as wide. Mature trees have massive twisting branches often supported by multiple trunks. The bark is rough and grayish. In full sun, leaves are dark green, leathery and medium sized. In shaded areas the leaves thin out and are larger, enabling them to maximize exposure to available sunlight.

Pines

Pine needles are actually leaves.

Coulter pine is a medium to large tree. It grows to 60 feet in height. It can be as wide as 40 feet. It has long needles that grow in dense bunches. Coulter pines are found in the Southern California inland foothills, usually above 3,000 feet in altitude. However, they do appear as low as 800 feet elevation on rocky slopes and undisturbed meadows. Coulter pines have enormous pine cones. These sharply barbed cones can reach over 1 foot long and weight more than 5 pounds.

Monterey pine (pinus radiata) grows quickly to 85 feet high and 35 feet wide. Its needles are dark green and about 5 inches long. These trees grow in coastal regions where fog and humidity relieves summer heat and drought.

Wildlife Value

Squirrels feed on the acorns of oak trees.

Live oak leaves and acorns feed mule deer, squirrels, scrub jays, acorn woodpeckers, wood rats and bears. The broad tree canopy provides shade and shelter to coyotes, deer and foxes. Owls nest in the branches and hummingbirds visit oak flower catkins.

Squirrels and jays eat coulter pine cone seeds. Squirrels gnaw the huge barbed cones off trees; otherwise the cones hang onto the tree for years. Cones open and release seeds after wildfires. These trees are used in reforestation projects.

Pinus radia is a home for squirrels, hawks and birds. The large pines have evolved to withstand summer drought. These pines do best near coastal areas. They suffer in extreme heat.

History

San Gabrielino Indians valued live oaks. They buried acorns next to streams and left them there to leach out their bitter compounds. After a few months, they ground the acorns into meal and used it for mush. Acorn-grinding stones are occasionally found by hikers in wilderness areas.

Large stands of native oaks were decimated by homesteaders in the 1800s. Farmers deemed live oaks a nuisance and dynamited them to make way for cropland. At the beginning of the 20th century, government stepped in to protect wooded hillsides and watersheds from timber harvesters.

Considerations

Pine needle litter can be a fire hazard.

Live oaks and both pine species are large trees. They quickly overwhelm small gardens. Although live oaks have deep root systems and do not usually cause home foundation problems, constant leaf litter can cause maintenance headaches when the tree overgrows roofs. Use live oaks in areas where their leaves can be left as a natural mulch. Keep them free from any summer irrigation.

The resin-rich pines can be a high fire danger. Both coulter and radiata pines drop copious amount of needles. Place these large trees in back of the garden, or in wilderness buffer zones. Coulter pine cones are heavy and thorned. Keep the trees away from patios or play areas.

References

• "Conifers of California" ; Ronald M. Lanner; 2002
• "Oaks of California"; Bruce M. Pavlik; 1995
• "Landscape Plants for Western Regions"; Bob Perry; 1992

Resources

• Theodore Payne Foundation: Quercus agrifolia
• National Center for Conservation Science and Policy: Monterey Pine