Quercus kelloggii (Californian black oak)

Botanical name

Quercus kelloggii

Other names

Californian black oak, California black oak, Kellogg oak

Genus

Quercus Quercus

Species

Q. kelloggii - Q. kelloggii is a rounded, deciduous tree with cracked, dark brown bark, elliptic, glossy, dark green leaves with bristle-tipped lobes. Leaves turn red, yellow, and orange in autumn as oblong to ovoid, green acorns ripen brown.

Native to

California, Oregon (United States)

Foliage

Deciduous

Tree shape

Spreading

Toxicity

Ingestion may cause severe discomfort.

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Colour

Flower

Insignificant or absent in Spring

Foliage

Dark-green in Spring; Dark-green in Summer; Dark-green in Autumn

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How to care

Watch out for

Pests

Also: Knopper gall wasps

Specific pests

Aphids , Oak gall wasps

Diseases

Also suffers from oak wilt in North America only.

Specific diseases

Oak wilt , Powdery mildew

General care

Pruning

Pruning group 1

Propagation methods

Grafting, Seed

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Monthly care advice

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Where to grow

Quercus kelloggii (Californian black oak) will reach a height of 20m and a spread of 15m after 50-100 years.

Suggested uses

Low Maintenance, Drought Tolerant, Architectural, Specimen tree

Cultivation

Grow in moderately fertile, well-drained, acid soil in full sun. Tolerates partial shade. Needs partial shade when young in areas with hot, dry summer. Moderately drought tolerant once established. Protect from grazing deer when young. Best planted in autumn in semi-arid climates.

Soil type

Chalky, Clay, Loamy, Sandy (will tolerate most soil types)

Soil drainage

Moist but well-drained, Well-drained

Soil pH

Acid

Light

Partial Shade, Full Sun

Aspect

North, South, East, West

Exposure

Exposed, Sheltered

UK hardiness Note: We are working to update our ratings. Thanks for your patience.

Hardy (H4)

USDA zones

Zone 10, Zone 9, Zone 8, Zone 7, Zone 6, Zone 5

Defra's Risk register #1

Plant name

Quercus kelloggii (Californian black oak)

Common pest name

Scientific pest name

Acute Oak Decline

Type

Other

Current status in UK

Present (Limited)

Likelihood to spread in UK (1 is very low - 5 is very high)

3

Impact (1 is very low - 5 is very high)

5

General biosecurity comments

Serious disorder of oaks likely to be caused by a complex of organisms. Eradication is not feasible; but good silvicultural practices could help to reduce spread and impacts.

Defra's Risk register #2

Plant name

Quercus kelloggii (Californian black oak)

Common pest name

Oak jewel beetle; Oak splendour beetle; Two -spot woodborer

Scientific pest name

Agrilus biguttatus

Type

Insect

Current status in UK

Present (Limited)

Likelihood to spread in UK (1 is very low - 5 is very high)

3

Impact (1 is very low - 5 is very high)

5

General biosecurity comments

Native beetle attracted to stressed trees and which is one of the biotic factors contributing to Acute oak decline. Good silviculture practice can help to mitigate the decline in tree health.

Defra's Risk register #3

Plant name

Quercus kelloggii (Californian black oak)

Common pest name

Ramorum leaf blight; Ramorum shoot dieback; Rhododendron twig blight; Sudden oak death

Scientific pest name

Phytophthora ramorum

Type

Oomycete

Current status in UK

Present (Limited)

Likelihood to spread in UK (1 is very low - 5 is very high)

4

Impact (1 is very low - 5 is very high)

4

General biosecurity comments

Pathogen of larch and other hosts subject to EU emergency legislation. A containment strategy is in place in the UK; reflecting its presence in wider environment/forestry settings in some areas. EU regulatory status is under review.

About this section

Our plants are under greater threat than ever before. There is increasing movement of plants and other material traded from an increasing variety of sources. This increases the chances of exotic pests arriving with imported goods and travellers, as well as by natural means. Shoot is working with Defra to help members to do their part in preventing the introduction and spread of invasive risks.

Traveling or importing plants? Please read "Don't risk it" advice here

Suspected outbreak? Click here for contact details to report to the relevant authority.

Date updated: 7^th March 2019 For more information visit: https://planthealthportal.defra.gov.uk/