SelecTree: Tree Detail
RING CUPPED OAK
Photo Locations: Cohn Arboretum - Baton Rouge, LA, Strybing Arboretum - San Francisco, CA, UC Berkeley Botanical Gardens - Berkeley, CA and The National Arboretum - Washington, DC
An attractive evergreen, suitable for gardens with mild winters. Leaves are dark green and leathery. Young leaves are tinted purple. Branches droop and are susceptible to breakage.
Native to Asia to Japan.
Additional Common Names
JAPANESE BLUE OAK, RING CUPPED OAK
Oval or Rounded Shape.
Has Evergreen foliage.
Height: 25 - 40 feet.
Width: 25 - 35 feet.
Growth Rate: 12 to 24 Inches per Year.
Leaves Ovate, Dark Green, No Change, Evergreen.
Flowers Inconspicuous. Brown. Flowers in Spring. Has separate male and female flowers on the same tree (monoecious).
Brown Acorn, Small (0.25 - 0.50 inches), fruiting in Spring or Summer Wildlife use it.
Bark Gray, Smooth.
Shading Capacity Rated as Dense to Very Dense in Leaf.
Litter Issue is Fruit and Leaves.
Tree Site Conditions & Constraints
Sunset Zones 7 - 9 and 14 - 21.
USDA Hardiness Zones 8 - 9.
Exposure Full Sun.
Wet but Well Drained Soil.
Clay, Loam or Sand Texture.
Acidic Soil pH.
Pests & Disease Information
Resistant to Verticillium. Susceptible to Armillaria.
Health, Safety & Environmental Concerns
Branch Strength Rated as Weak.
Root Damage Potential Rated as Low.
Attracts Birds and Squirrels.
Not Deer Palatable.
Wildlife use Fruit.
Special Uses & Values
Buffer Strip, Shade Tree or Street Tree.
Cite this tree:
SelecTree. "Quercus glauca Tree Record." 1995-2018. Dec 19, 2018.
< https://selectree.calpoly.edu/tree-detail/quercus-glauca >