Tanoak Plant Care

Tanoak (Notholithocarpus densiflorus) belongs to the Fagaceae family within the Notholithocarpus genus. Tanoak is native to the far western United States, particularly Oregon and California. Tanoak is also known as Tanbark Oak.

Tanoak displays a tall, evergreen tree growth habit, reaching up to 60 ft tall with a spread of approximately 30 ft. Tanoak produces inconspicuous catkins.

Leaf size: approximately 6 inches.

Water a young or newly planted Tanoak 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.

Tanoak thrives in full sun to partial shade.

Notholithocarpus densiflorus tolerates temperatures of 50–80°F. Tanoak prefers humidity levels of 40–70%.

Well-draining, acidic soil with high organic content. Good drainage is essential for Tanoak to prevent waterlogging, which leads to root rot and fungal issues.

Feed Tanoak every 8 months during the growing season with a balanced, slow-release fertilizer at the rate on the label. Established trees in good soil often need little extra feeding, so let weak growth or pale foliage guide you.

Stop feeding by late summer so new growth can harden before winter.

The PlantoScan app can remind you when to water and when to fertilize each plant.

Choose a spot with full sun to partial shade and well-draining, acidic soil with high organic content. Avoid low spots where water collects after rain.

Tanoak is suited to USDA Zone 12a.

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.

Tanoak can spread to about 30 ft (9.1 m) and reach about 60 ft (18 m) tall. Space plants about 30 ft (9.1 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.

Prune Tanoak 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.

Tanoak is frost-tender (hardy to USDA zone 12). In colder areas grow it in a container and move it to a bright, frost-free place before the first frost.

Tanoak can be propagated through seeds, root cuttings.

See all plants toxic to cats and plants toxic to dogs.

Tanoak is susceptible to oak root fungus, oak twig pruner, oak leafroller. 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.

Tanoak grows outdoors in USDA Zone 12a. It survives winters down to planting zone 12a. Tanoak is native to the far western United States, particularly Oregon and California. In cooler regions, grow Tanoak as a houseplant or bring it indoors before the first frost.