Blue Oak
Quercus douglasii
Last reviewed: June 2026
Blue Oak (Quercus douglasii) is not on the ASPCA Animal Poison Control Center toxic plant list for dogs or cats (aspca.org, last reviewed 2026-05-21). If your pet shows symptoms after eating any plant, call the ASPCA at (888) 426-4435.
Light
full sun
Water
low
Size
300"–600" H × 300"–600" W
Bloom
Mar, Apr, May
Native to
CA
Pollinators
bees, beetles
Browse plants for this ecoregion
Blue oak is a stately native tree with distinctive blue-green foliage and a broad, rounded canopy. It grows slowly but can live for centuries, eventually reaching heights of 25-50 feet. This drought-tolerant tree adapts well to Mediterranean climate zones and requires minimal irrigation once established.
In an HOA neighborhood
Blue Oak is an HOA-friendly choice in the right placement. Maintenance level: moderate. Tidiness: 3 out of 5.
Works well in: backyard only, street edge, mid zone.
- Mature size (25-50 feet) may exceed HOA height restrictions
- Acorn drop can create seasonal maintenance issues
- May not fit smaller front yard spaces due to spread
Wildlife value
Blue oaks support numerous wildlife species, producing acorns that feed deer, squirrels, jays, and other animals. During spring bloom months, their catkins provide important early-season pollen for bees and beetles.
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.
Does Blue Oak fit your yard? Open it in Pollinator Patch to check it against your sun, soil, and HOA-conscious filters.