California Black Oak
Quercus kelloggii
Last reviewed: July 2026
California Black Oak (Quercus kelloggii) is a native deciduous tree found in California and Oregon that blooms April through May. This drought-tolerant oak supports native pollinators including bees and beetles.
California Black Oak (Quercus kelloggii) is not on the ASPCA Animal Poison Control Center toxic plant list for dogs or cats (aspca.org (opens in new tab), last reviewed 2026-05-21). If your pet shows symptoms after eating any plant, call the ASPCA at (888) 426-4435.
The USDA PLANTS Database (opens in new tab) does not flag California Black Oak as toxic to livestock.
Light
full sun
Water
low
Size
144"–600" H × 240"–480" W
Bloom
Apr, May
Native to
CA, OR
Pollinators
bees, beetles
Browse plants for this ecoregion
A majestic, deciduous native tree that can reach heights of 12-50 feet with a broad, spreading canopy. It features distinctive lobed leaves that turn golden yellow to orange in fall before dropping. This oak blooms in spring with subtle catkins that later produce acorns.
Growing California Black Oak
Grow California Black Oak in full sun and low water. Mature plants reach 144 to 600 inches tall and spread 240 to 480 inches wide. Expect moderate maintenance to keep it looking intentional in a front yard.
In an HOA neighborhood
California Black Oak is an HOA-friendly choice in the right placement. Maintenance level: moderate. Tidiness: 3 out of 5.
Works well in: mid zone, street edge.
- Extremely large mature size may conflict with HOA preferences
- Leaf drop in fall requires seasonal cleanup
- Acorn production can create maintenance concerns on hardscapes
Wildlife value
Host plant for California sister butterfly, California hairstreak.
This oak provides substantial habitat value, supporting bees and beetles with its spring blooms. Its acorns are a crucial food source for numerous wildlife species including birds, deer, and small mammals.
Common questions
- Where does California Black Oak naturally grow?
- California Black Oak is native to California and Oregon, typically growing in mountain slopes and mixed conifer forests at elevations between 1,000 and 8,000 feet.
- When does Quercus kelloggii bloom?
- California Black Oak blooms from April through May, producing inconspicuous flowers that are wind-pollinated along with visits from bees and beetles.
- What pollinators visit California Black Oak?
- While primarily wind-pollinated, California Black Oak flowers attract bees and beetles that feed on pollen and help support local pollinator populations.
- Is California Black Oak toxic to dogs?
- California Black Oak is not on the ASPCA Animal Poison Control Center toxic plant list for dogs (aspca.org).
- Is California Black Oak toxic to cats?
- California Black Oak is not on the ASPCA Animal Poison Control Center toxic plant list for cats (aspca.org).
- Is California Black Oak toxic to livestock?
- The USDA PLANTS Database does not flag California Black Oak as toxic to livestock.
- Is California Black Oak HOA-friendly?
- California Black Oak is generally an HOA-friendly choice in the right placement, with moderate maintenance.
Native range data from the USDA PLANTS Database and regional native plant society lists. Pollinator and host plant associations compiled from GBIF, iNaturalist, and published ecological literature.
Ready to grow California Black Oak? Add it to your garden in Pollinator Patch to track it and get season-by-season care guidance.
Not sure where to start? Take the 2-minute yard quiz