Photo: no rights reservedCC0 1.0via iNaturalist
California Black Oak Plant Care
Quercus kelloggii Newb.
Updated · Sources · How we source care data
This plant's large, lobed leaves with a glossy dark green surface are a standout feature. Originating from the western United States, Quercus kelloggii's beautiful foliage and impressive size make it a sought-after addition for plant collectors looking to add a stately presence to their landscape.
Every 7–14 days
Full sun
20–100°F
30–70%
At a glance
How do you care for California Black Oak?
Plant California Black Oak in full sun (USDA zones 6a–9b) and water a young tree every 7–14 days until it is established. It tolerates temperatures of 20–100°F (-7–38°C).
Where Is the California Black Oak Native To?
What Is the California Black Oak?
California Black Oak (Quercus kelloggii) belongs to the Fagaceae family within the Quercus genus. California Black Oak is native to western North America. California Black Oak is also known as Black Oak.
California Black Oak displays a large deciduous tree growth habit, reaching up to 80 ft tall with a spread of approximately 60 ft. California Black Oak produces inconspicuous catkins.
Leaf size: approximately 6 inches.
How Often Should You Water a California Black Oak?
Water a young or newly planted California Black Oak every 7–14 days, soaking the whole root zone, until it is established — usually one to two growing seasons. Established trees mainly need water during long dry spells. In a container, water whenever the top few centimetres of soil are dry.
Watering Frequency
Every 7–14 days
Until established; then in dry spells
What Light Does the California Black Oak Need?
California Black Oak thrives in full sun.
Light Requirement
Full sun
What Temperature and Humidity Does the California Black Oak Prefer?
Quercus kelloggii tolerates temperatures of 20–100°F. California Black Oak prefers humidity levels of 30–70%.
Temperature
20–100°F
Humidity
30–70%
What Soil Mix Works Best for a California Black Oak?
Well-draining loamy soil with good organic content. Good drainage is essential for California Black Oak to prevent waterlogging, which leads to root rot and fungal issues.
Where Should You Plant a California Black Oak?
Choose a spot with full sun and well-draining loamy soil with good organic content. Avoid low spots where water collects after rain.
California Black Oak is suited to USDA Zone 6a – 9b.
Plant container-grown or balled-and-burlapped trees in spring or early autumn, setting the root flare at soil level, and water well after planting.
How Far Apart Should You Plant a California Black Oak?
California Black Oak can spread to about 60 ft (18.3 m) and reach about 80 ft (24 m) tall. Space plants about 60 ft (18.3 m) apart so mature crowns don't crowd each other, and plant at least half that distance from buildings, fences and paths.
Planning a row or hedge? Try the tree spacing calculator.
How Do You Prune a California Black Oak?
Prune California Black Oak while it is dormant in late winter: first remove dead, damaged and crossing branches, then thin lightly for shape.
If it flowers in spring, prune right after flowering instead so you don't remove next year's buds. Never take off more than about a quarter of the tree in one year.
How Do You Care for a California Black Oak in Winter?
California Black Oak is hardy down to USDA zone 6a, so once established it can stay outdoors through winter in that zone and warmer ones.
Water deeply in late autumn before the ground freezes, and spread a 5–8 cm (2–3 in) layer of mulch over the root zone, keeping it away from the trunk.
Young and container-grown trees need extra protection: roots in a pot freeze much more easily than roots in the ground.
How Do You Propagate a California Black Oak?
California Black Oak can be propagated through acorns, grafting. Similar propagation techniques also apply to english oak plant care, which shares the same genus.
Is the California Black Oak Toxic to Pets and Children?
Pet safety not verified
The ASPCA does not list California Black Oak, so we can't confirm whether it is safe for cats and dogs. Keep pets from chewing it as a precaution.
This is a general caution, not veterinary or medical advice. If your pet ate a plant, contact your vet or animal poison control.
See all plants toxic to cats and plants toxic to dogs.
What Pests and Diseases Affect the California Black Oak?
California Black Oak is susceptible to oak leaf blister, oak wilt, gypsy moth. Inspect the foliage regularly, especially along leaf undersides and stems. Treat infestations promptly with insecticidal soap or neem oil to prevent spread.
Yellow leaves, brown tips or drooping? See common plant problems and how to fix them.
What USDA Hardiness Zone Does the California Black Oak Need?
California Black Oak grows outdoors in USDA Zone 6a – 9b. It survives winters down to planting zone 6a. California Black Oak is native to western North America.
Hardiness Zone
Zone 6a – 9b
Keep exploring plants
California Black Oak is one of many species covered in the complete plant care and identification guide, which groups plants by genus, attribute, and popularity.
It belongs to the Quercus genus — compare its care with other Quercus species on PlantoScan.
Quercus is part of the Fagaceae plant family — browse all Fagaceae genera and species.
California Black Oak thrives in bright light and direct sun — see other bright-light plants.
More Quercus Species
Other Quercus species in PlantoScan's care catalogue share similar watering, light, and soil preferences:
Sources
- Scientific name & taxonomy: Quercus kelloggii Newb., family Fagaceae (first published in Pacif. Railr. Rep. Williamson & Abbot, Bot. 6(3; 2): 28, 89 (1858)) — World Flora Online record, IPNI name record.
- Pet toxicity: Pet safety not verified: the ASPCA does not list California Black Oak, so we can't confirm whether it is safe for cats and dogs. Checked against the ASPCA plant list; any other toxicity note on this page comes from PlantoScan's plant database.
- Photo: Public domain, CC0 1.0, iNaturalist — original.
- Hardiness zone: USDA Zone 6a – 9b, estimated from the plant's typical growing conditions.
- Care values(watering, light, temperature, humidity, soil, fertilizing): PlantoScan's plant database, filtered by automatic plausibility checks — values that fail them are hidden. How we source and check plant data.
Spotted a mistake? Email info@upvision.media with the page link — we check and correct reported errors.
Identify Plants Like the
California Black Oak Instantly
Scan any plant with your phone camera and get instant ID, care tips, water and fertilizer reminders, and health checks — all in one app.
Free
to download
iOS & Android
platforms
Light & dark
mode
100,000+
species