About
Quercus glauca, the Japanese blue oak, is a medium-sized, evergreen tree producing thick, leathery, dark-green, ovate to oblong leaves that are glaucous blue-green beneath and often bronze or purple when young. Small acorns about 2 cm long are produced in autumn. An ornamental and architectural evergreen oak for a sheltered, sunny, well-drained garden.
About the genus
Quercus, the oaks, are deciduous or evergreen trees and shrubs with characteristic acorn fruits, lobed or toothed leaves and inconspicuous flowers. Among the most important, long-lived and ornamental of all trees.
Growing conditions
SunlightFull sun
Soil typeClay, Loam, Sand
Soil pHAcid, Neutral
Soil moistureMoist but well-drained, Well-drained
AspectEast-facing, South-facing, North-facing, West-facing
ExposureSheltered
UK hardinessH4
Plant details
Plant typeTrees
HabitBushy
FoliageEvergreen
Height8-12 metres
Spread4-8 metres
Time to full height20-50 years
Suggested usesArchitectural
Native toJapan, China
FragranceFlower
ToxicityPets (dogs): Harmful if eaten - for further information and contact numbers regarding pets, see the HTA guide to potentially harmful plants
Care notes
CultivationGrow in deep, fertile, well-drained soil in full sun, with shelter from cold winds and late frosts
PruningPruning group 1
PropagationPropagate by seed sown in a coldframe or seedbed as soon as ripe or by grafting in mid-autumn or late winter
Pest resistanceMay be susceptible to oak processionary moth, aphids, caterpillars, leaf-mining moths and oak gall wasps
Disease resistanceMay be susceptible to powdery mildews and honey fungus