Tanoak (Lithocarpus densiflorus)

At a glance

Lifecycle: Perennial (hardy)
Exposure: Full sun
Frost limit: −17.8 °C

Cultivation

Prefers a deep fertile soil with medium drainage. Perfectly hardy at Kew, trees produced seed at Kew in the very hot summer of 1989[K]. A slow-growing tree in the wild, living up to 300 - 350 years old. Plants usually flower in the spring and sometimes again in the autumn.

Propagation

The seed is best sown as soon as it is ripe in the autumn in a cold frame. It needs to be protected from mice, squirrels and other seed eaters. The seed has a short viability but can be stored for a few months if kept cool and slightly damp - the salad compartment of a fridge is a good storage place. Germination takes place in the winter or early spring. When they are large enough to handle, prick the seedlings out into individual pots. If the plants are 15cm or more tall by the summer they can be planted out into their permanent positions. Give them a good weed-excluding mulch and some protection from the cold for their first couple of years outdoors. If growth is not sufficient then grow them on in the greenhouse for their first winter and plant them out into their permanent positions in late spring or early summer, after the last expected frosts.

Edible uses

Seed - cooked. The seed is valued for its oil.

Medicinal uses

The bark is very astringent. An infusion is used as a wash for face sores.

Material uses

The bark is exceedingly rich in tannin, yielding up to 29%. It has been used as a brown dye and also to preserve rope that is being used in water[257, K]. Wood - hard, strong, close grained, brittle. It is not commercially important and is used mainly for fuel.

Habitat

Woody slopes below 1500 metres.

Native range

South-western N. America - Oregon and California.

Scientific synonyms Notholithocarpus densiflorus