Quercus kerrii Seeds | Kerr’s Oak

Glossy leaves and acorns in scaly cups of Kerr's Oak (Quercus kerrii) — Kerr’s Oak (*Quercus kerrii*): Fagaceae, a ring-cupped oak of the hill forests of Southeast Asia and southern China.

LATIN NAME: Quercus kerrii

COMMON NAME: Kerr’s Oak, Southeast Asian Oak

Plant Profile

Kerr’s oak is a semi-evergreen oak of the hill forests of Myanmar, Thailand, Laos, southern China and Hainan, growing fifteen to twenty-five metres tall with a rounded crown and a trunk that is often buttressed at the base. The leaves are glossy, leathery and narrowly oval, with a few shallow teeth, and they cling to the branches through the dry season.

The acorns sit in shallow, scaly cups and ripen in autumn, and the new growth appears in a soft bronze before it hardens to deep green. It belongs to the ring-cupped oaks, a group treated by some botanists as a separate genus, Cyclobalanopsis.

Science & Biotechnology

The ring-cupped oaks of tropical Asia are a focus of oak taxonomy, since their relationships to the temperate oaks have been debated for more than a century. Molecular work has confirmed that they sit within Quercus, but their species limits are still unclear in places where several taxa meet.

Research on Kerr’s oak has also looked at its acorn biology and at the mycorrhizal fungi it needs, since oaks in these forests depend on ectomycorrhizal partners for establishment. Forest surveys in Hainan record it as uncommon, and its habitat has been reduced by clearance for rubber and cashew.

Uses & Benefits

The wood is hard, heavy and durable, used locally for construction, furniture and tool handles, and the tree is sometimes left standing in cleared land for shade and later harvest. In the garden it is a stately tropical or subtropical shade tree for a large property, with evergreen foliage and acorns that feed wildlife.

It is not a tree for a small plot, and it needs a frost-free climate with a distinct dry season to do well. The acorns are bitter with tannins and need leaching before they can be eaten, as with most Asian oaks, and they are more useful as pig feed than as human food.

In Thailand and Vietnam the tree is also planted in temple grounds, where old specimens are protected.

Growing from Seed

Acorns lose viability quickly, so sow them fresh in autumn, two centimetres deep in a deep pot of free-draining mix, and keep at 20-25C. Germination is usually within a month.

The seedling develops a long taproot in its first season, so use a tall container and avoid root disturbance. Grow it in partial shade for the first year, then plant out in full sun in deep, well-drained soil; the tree needs warmth and will not tolerate hard frost. Water the young tree deeply once a week in its first dry season, then reduce. A mulch of leaf litter keeps the roots cool and moist. Avoid pruning the leader, which spoils the shape of the crown.

Our Take

Kerr’s oak is a tree for the tropics and for the patient. Its glossy leaves and ringed acorns are worth the wait, but it needs space, warmth and a long-term plan.

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