Does it need summer water?

Established trees prefer dry summers and may suffer from root rot if irrigated during the hot months.

How fast does it grow?

It is a moderate grower, typically adding 30 to 60 centimeters of height per year.

Plant guide

Coast live oak.

Quercus agrifolia

Pronounced KWER-kus ag-ri-FOH-lee-uh

Also known as California live oak, Coast Live Oak

The coast live oak is a beautiful, evergreen tree native to the California coast. It's known for its iconic rounded canopy and holly like leaves. These trees are a cornerstone of their ecosystem and provide habitat for many local species.

Another photo of Coast live oak — Photo by Daniel Cahen (CC BY) via iNaturalist

At a glance

Care level: Easy
Plant type: Tree
Light: Full sun
Indoor light: Direct sun
Water: Every 14 to 30 days
Mature size: 20 to 80 feet
Growth rate: Medium
Hardiness: USDA 8 to 10
Bloom time: Early to mid spring

Care

Plant this tree in a spot with plenty of space for its wide root system. Avoid overwatering once established, as summer water can lead to root rot. Watch for signs of sudden oak death or leaf spots to keep it healthy.

Watering: Young trees need regular water, but mature trees prefer to stay dry during the summer.
Feeding: Generally does not need fertilizer if planted in native soil.
Pruning: Prune only to remove dead or crossing branches during the dormant winter season.
Repotting: These are best planted directly in the ground as they develop deep taproots.
Soil: Well draining loam or clay
Soil pH: 6.0 to 7.5
Temperature: -7 to 38°C
Humidity: 20 to 60%
Drought tolerance: High
Lifespan: Perennial, typically 100 to 250 years.
Deer and rabbits: Moderate

Signs it needs repotting

Roots circling the bottom of the pot
Stunted growth during the active season

Safety

People: The plant is not considered toxic, but the high tannin content in raw acorns can cause digestive upset.
Children: The sharp, prickly leaf margins can scratch young children, so it is best planted away from play areas.
Contact allergens: The stiff, holly like leaves can cause minor skin scratches if handled without gloves.
Airborne allergens: The windborne pollen produced in spring is a common cause of seasonal allergies.
Edibility: Acorns contain high levels of tannins and require extensive leaching before they are safe for human consumption.

How to identify it

Evergreen leaves with spiny margins
Dark gray and furrowed bark
Rounded and dense canopy shape
Small acorns with cap scales
Leaves are cupped or convex

Height: 6 to 25m
Spread: 5 to 30m
Leaves: dark green, evergreen
Flowers: yellow, green, 0.5 to 1cm
Fruit: brown, Autumn

Problems to watch for

Gall WaspsCommon
Oak MothCommon
Sudden Oak DeathCommon
Leaf ScorchUncommon
Oak BorerUncommon
Oak Leaf BlisterUncommon
Oak MildewUncommon
Oak WiltRare

By symptom

Plant problems by symptom

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Growing it

Propagation: seed
When to plant: autumn, winter
Overwintering: No special care is needed as it is fully adapted to its native climate. Keep the area around the trunk clear of mulch to prevent moisture buildup.
In containers: It is not suitable for long term container growth due to its massive size and deep taproot requirements.

Seed

Collect fresh acorns in autumn as soon as they fall.
Float test them in water and discard any that do not sink.
Plant immediately in deep pots to accommodate the long taproot.
Keep the soil lightly moist until germination occurs in spring.

Avoid planting thirsty garden perennials directly under the drip line to prevent crown rot.

Grows well with

California Sagebrush · They share similar drought requirements and thrive in the same coastal scrub habitat.
Toyon · This shrub provides a beautiful evergreen understory that complements the oak.
Coffeeberry · It is a reliable companion that tolerates the dry shade beneath the oak canopy.

Similar species

Interior Live Oak · It is very similar but better adapted to hotter, inland climates.
Canyon Live Oak · It has a similar evergreen habit but prefers cooler, mountainous regions.

Science

Family: Fagaceae
Genus: Quercus
Order: Fagales
Class: Magnoliopsida
Native range: Coastal California and northern Baja California.
Conservation: It is not currently endangered, but it faces significant threats from sudden oak death syndrome and habitat loss.

It survives in Mediterranean climates by utilizing deep taproots to access groundwater during long, rainless summers.

Value to wildlife: larval host plant, provides nesting cover, acorns feed mammals and birds
Pollinators: bees, butterflies, moths
Uses: shade tree, wildlife garden, erosion control, coastal windbreak

Through the year

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Flowering

Fruiting

Foliage

Ecological indicators

Salinity: 2/9
Soil reaction: 6/9
Light: 7/9
Temperature: 7/9
Moisture: 3/9
Nutrients: 4/9

Taxonomy resolved against GBIF.

Questions people ask

Does it need summer water?: Established trees prefer dry summers and may suffer from root rot if irrigated during the hot months.
How fast does it grow?: It is a moderate grower, typically adding 30 to 60 centimeters of height per year.

Where the name comes from

The species name agrifolia means field leaf, referring to the resemblance of its leaves to those of the European holly.

Good to know

The coast live oak is one of the most characteristic native oaks of California's coastal environments.
These trees can live for over 250 years in the right conditions.
The wood is extremely hard and was historically used for making charcoal.
They are well adapted to survive wildfires by resprouting from the root crown.

Also in

Drought-tolerant plants

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This guide was generated with AI on September 26, 2026 and checked against GBIF taxonomy. It is general information, not horticultural or veterinary advice. Read about how we build these guides.