Quercus douglasii
Blue oak · also Mountain oak, Iron oak, Mountain white oak
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A mature blue oak is a medium-sized tree with a rounded canopy of deciduous, dull bluish-green leaves. It is California's most drought-tolerant deciduous oak, thriving on hot, dry foothills. Reproduction is failing in much of its native range due to various factors, making natural replacement difficult.
Where it grows
Trees in each city's inventory, with the share of that city's named trees this species accounts for.
- 200.01%0.5 yr3.0 in
Traits
- Form
- Broadleaf
- Foliage
- Deciduous
- Mature height
- 50–70 ft
- Canopy spread
- 40–50 ft
- Growth rate
- Fast
- Water needs
- Low
- Drought tolerance
- High
- Wildlife value
- High
- Blooms
- Mar, Apr, May
Trunk diameters across every city: median 3.0 in, mean 3.0 in, 90th percentile 3.0 in. Measured at breast height, as published by each inventory.
Native range
Terrestrial ecoregions where this species is native. Trees in the dataset mostly stand well outside it.
Mediterranean Forests, Woodlands & Scrub
- California coastal sage and chaparral
- California interior chaparral and woodlands
- California montane chaparral and woodlands
Temperate Grasslands, Savannas & Shrublands
- California Central Valley grasslands
Other Quercus in the catalogue
74 of the top 2,000 species are in this genus.
