Oak Woodlands

The Problem

The Word "Acorn"

Oak Flowers

Leaf Galls


Natural Planting

    Annual Weeds

Life in Mature Trees
    "Spanish Moss"
     Leaping Lizards
     Diseases, Decline
     Sudden Oak Death

Key to Oak Species

     Planting Trees
     Climate Change

Common Tree Oaks in California

Illustrations: Michael Lee, Good Nature Publishing, Seattle, WA who publish a great oak poster!
Illustrations used with permission,but are copyrighted by Good Nature Publishing, and artist.

Click on Thumbnails below for larger picture    


Blue Oak

Endures in the hot, dry, interior foothills where temperature exceeds 100°F. Generally below 3500 feet. Often borders chaparral and grasslands.


Black Oak

In diverse mountain landscapes 2,000 to 6,000 feet,with either conifer or broadleaf trees (Ponderosa pine, white fir, incense cedar, and sugar pine are common associates). Vibrant fall yellows and reds. Found where annual rain exceeds 25 in., where snow is common.


Canyon Live Oak

Evergreen, in foothills, mountain canyons and on upland slopes to 9,000 feet. Leaves 1-2.5 " long, some with spiny or toothed margins, some with smooth margins on same tree! Boulder strewn canyons, often with deep litter layers. Golden flecks under leaf surfaces.


Interior Live Oak

Evergreen, on upland slopes below 5,000 feet, across low foothills, in canyons, where summers are hot and dry. Leaves are flat, leathery, 1-3 " long, margins can be smooth, toothed or spiny but leaves do not have tufts of hairs underneath where veins meet midline.


Island Oak

Occurs on Channel Islands- Santa Cruz, Santa Rosa, etc. and as landscape tree near Santa Barbara. Moist sites with some fog, often north-facing hillsides.


Engleman Oak

In rare scattered groves along western edge of interior deserts. Occurs on sites above dry coastal plains, and below cold mountians. Name "mesa" refers to tendency to grow near basalt caps of mesas.


Oregon Oak

Upland slopes, ridges and open valley bottoms away from coastal fog belt, between 1,000 and 4,000 feet. Occurs on many soil types, often with Douglas fir, madrone, black oak, and with junipers in drier, interior sites.


Valley Oak

Monarch of California oaks, can have stems six feet in diameter. Winter deciduous, leaves 2-4 " long. Found at least one ridge inland from coastal fog zone, prefers rich bottomland, deep soils, often below 2,000 feet.


Coast Live Oak

Evergreen, in fog zones up to 5,000 feet. Tolerates some salt spray. Dark green, cupped, hard leaves with dense tufts of hair underneath where veins meet midrib. Leaves have sharp spines on edges.