PlantFun
Plant Needs
Sunlight
Full sun to partial shade; tolerates coastal fog and windy conditions without significant damage
Watering
Established mature trees are highly drought-tolerant; water young trees deeply every 1-2 weeks during dry spells
Temperature
Tolerates mild frost and coastal heat; avoid prolonged exposure to temperatures below -5°C
Characteristics
- Leaf: Thick, leathery, oblong leaves with spiny margins; glossy dark green upper surface, pale gray-green underside
- Flower: Male catkins are yellow-green, pendulous; female flowers are small, reddish, axillary
- Stem/Bark: Mature bark is thick, furrowed, dark brown to gray; young stems are smooth and green
Care Guide
Watering
Water young trees deeply every 1-2 weeks; established trees need no supplemental water in most years
Fertilization
Apply slow-release balanced fertilizer once in early spring. Fertilize only young, newly planted trees to support establishment
Composted eggshell powder：Sprinkle a thin layer around the tree’s drip line in early spring; avoid direct contact with the trunk to prevent bark burnPruning
- Remove dead, diseased, or crossing branches in late winter to early spring to maintain canopy health
- Thin dense inner branches to improve airflow and light penetration
- Avoid heavy pruning; retain the tree’s natural spreading, rounded form
- Trim suckers growing from the base to redirect energy to the main canopy
Toxicity
Warning: this plant may be toxic.
Pets & Humans
Pets: ASPCA: Toxic; gallotannins may cause gastrointestinal irritation and potential kidney damage in severe cases
Humans: Ingestion of large amounts of acorns or leaves may cause mild gastrointestinal upset
Garden Uses & Culture
Culture: Symbolizes strength and longevity in California coastal ecosystems; valued in native landscaping for wildlife support
Usage: Ornamental shade tree; provides habitat and food for birds, mammals, and pollinators
