Close-up of Canyon Live Oak acorn and leaves, autumn. Photo copyright © 2019 Mariposa Native Plants
The Canyon Live Oak is the most widely-distributed oak tree in California. It is found from the Oregon border, south along both sides of the Central Valley, and into Baja California. It is mostly absent from the Central Valley proper, from the eastern slope of the Sierra Nevada, and from the Mojave Desert. It is one of two live oaks found in Mariposa County, the other being the Interior Live Oak (Quercus wislizeni).
Both the Canyon Live Oak and the Interior Live Oak have leaves that are dark green above, with either finely toothed or smooth edges. However, the bottom of the Q.chrysolepis leaf is rough, yellowish, and leathery, whereas the bottom of a Q.wislizeni leaf is medium green and shiny. The acorns of the two oaks are very different. Q.chrysolepis has a squat, rounded acorn, with a distinctly fuzzy, golden base cap. But Q.wislizeni acorns are long, thin, and bullet-shaped.
Canyon Live Oak leaf bottom (left) and Interior Live Oak (right). Photo copyright © 2019 Mariposa Native Plants
Elevation: higher foothill slopes and into the mountains at 9,500 ft. (3,000m). The Interior Live Oak is found at lower elevations, up to around 3,000 ft. (1000m), mixed in with Gray Pines (Pinus sabiniana). The Canyon Live replaces the Interior Live Oak at higher elevations, beginning around 2,500 ft., with Ponderosa Pines (Pinus ponderosa) as companion trees. Sun: partial or full. Temperature: cold tolerant to -20°F (-30°C). Soil: poor, clay, loamy, or sandy; pH 5-8.
Oak trees are difficult to transplant, because of their sensitive roots. This tree needs a site that is well-drained and given full or partial sunlight. The roots are sensitive to disturbance; avoid breaking the root ball when planting from the container. The best times to plant them from a container is in the fall or winter, as late as the beginning of February. If the ground is dry, drench the ground around the tree with water after planting, making sure that the top of the root ball is level with ground around the tree. It is helpful to dig the hole down several inches below where the root ball will sit and fill it with loose, original soil, so as to better facilitate penetration by the oak tap root. Planting acorns is more reliable as a method for establishing Canyon Live Oak on a landscape. It is also prudent to install a wire screen around the tree, attached to a firmly-planted stake, for the first few years; this prevents browsing by herbivores (especially deer). Water (2 gallons, 8 liters) once per week in the first summer. Water no more than once per month, in the same amounts, in the second summer. Thereafter, no supplemental water should be required. If the third spring before summer is especially dry, then water in the third summer as in the second. Thereafter, no supplemental water should be required. Nota bene: Established California native oak trees should never be watered in the warm spring, summer, and fall months.
Q.chrysolepis is a host plant for a number of butterflies, including the prominent Western Tiger Swallowtail and California Sister in Mariposa County.
Canyon Live Oak tends to grow with a straighter, more singular trunk than Interior Live Oak, and thus it is generally preferred for aesthetic reasons.
Native Americans relied on Canyon Live Oak acorns as a food staple, but only after they leached out the tannins. After roasting, the acorn was used as a coffee substitute by native peoples as well as by settlers.
Seedlings in deep pots (early spring only), in #1 containers (spring and summer), and acorns (12/bag) beginning in late summer.