Blue oak
Quercus douglasii Hook. & Arn.
- light
- Full sun
- water
- Little
- tall
- 9.1 m
- wide
- 9.1 m
Fagaceae
Also called Blue Oak, Iron Oak, Mountain Oak
Formerly Quercus ransomii
When it flowers
JFMAMJJASOND
Not known yet in the tropics: too few flowering observations to read a season from.
PetsNo pet-safety information yet
PeopleNo safety information yet
If a child, a pet or anyone may have eaten a plant, contact a doctor or vet straight away, or call the National Poisons Information Centre (AIIMS, New Delhi) on 1800 116 117, free and open 24 hours.
Something wrong with it?About it
- Grows as
- TreeKew's checklist, not yet checked
- Climate
- SubtropicalKew's checklist, not yet checked
- Wild in
- CaliforniaKew's checklist, not yet checked
- Light
- Full sun (6 h or more)Read from Wikipedia and PlantLust, checked by a majority of its sourcesBacked by both sources
- Height
- 6.1 m to 12 mRead from PlantLust, one source
- Spread
- 6.1 m to 12 mRead from PlantLust, one source
- Water
- Little: takes droughtRead from Wikipedia and PlantLust, checked by a majority of its sourcesBacked by both sources
- Coldest it survives
- -12.2 °C (USDA zone 8a)Read from PlantLust, one source
Not known yet: flowers, heat, hottest it survives.
Where this comes from
- Wikidata, read 2026-10-25, CC0-1.0
- Kew's checklist, read 2026-10-24, CC-BY-4.0
- Wikipedia, read 2026-10-25, fact, cited
- PlantLust, read 2026-10-25, fact, cited
- Wikimedia Commons, read 2026-10-25, CC BY-SA 3.0
- 3D model: Quercus douglasii (built for Vanagrha) by Vanagrha, own
A fact “checked by a majority of its sources” was settled by a vote of the pages it was read from, not by a person reading it; one marked “one source” rests on that page alone. Anything else not marked checked has not been checked yet. Where nothing is known, the page says so rather than guess.