Sessile oak (Quercus petraea): what the forestry bodies record

This page reports what forestry bodies say about one tree. It does not identify trees from descriptions or photos and does not say what should be done with any tree. Each fact names its source, all read on October 9, 2026. The pests and diseases of oak that this site profiles are gathered in what attacks oak, and the other native British oak has its own page on pedunculate oak.

At a glance

Item	What the source records
Scientific name and family	Quercus petraea, family Fagaceae (Woodland Trust)
Origin	Native (Forest Research and Woodland Trust). Forest Research files it as Sessile oak with the code SOK and calls it a Principal tree species.
Height	20 to 40 m, deciduous broadleaf (Woodland Trust)
Rainfall, exposure, shade	More than 600 mm of rain preferred; moderate exposure; intolerant of shade (Forest Research key properties)

Range

Forest Research says sessile oak is native to the British Isles and to much of western, central and eastern Europe. In Britain it tends to have a more westerly and upland distribution than pedunculate oak, and it is prominent in the west of England, Wales, Scotland and Ireland. The entry adds that the natural distribution has been much influenced by plantations in earlier centuries. It records a hybrid of the two oaks, Quercus x rosacea, widely distributed in Britain, with features of both parents that can make identification difficult. The Woodland Trust calls it the national tree of Ireland, native to most of Europe and commonly found in hilly regions. EUFORGEN, the European forest genetic resources programme, calls it a long-lived deciduous tree native to most of Europe, often found in upland areas where it forms mixed forests with other broadleaf species.

Site and soil

Forest Research describes a tree that is cold hardy and generally windfirm, but open to damage from late spring frosts. It says the tree tolerates exposure but develops poor form, and that it grows on mineral soils of poor or medium nutrient status. The entry says it tolerates slightly drier soils than pedunculate oak and is not suited to compacted or wet soils. It lists a preference for light, well drained but moist soils. EUFORGEN says the tree needs light and does best on fertile, acidic to neutral soils that drain well, and that it is quite resistant to drought compared with pedunculate oak. Forest Research adds that it has a deep rooting system, lacks apical dominance, tends towards a bushy shape if open grown and coppices well.

Leaves, flowers and acorns

The Woodland Trust describes dark green lobed leaves with an undulate margin, shallow lobes and a long leaf stalk. Male flowers are green catkins and female flowers are small clusters of bracts, both on the same tree. The acorn sits directly on the twig with no stalk, and sessile means stalkless. In winter the Woodland Trust names rounded buds in clusters, each with more than three scales. It says the trunk is more upright and the branches straighter than on English oak, and that the two species often hybridise. It adds that one oak can produce as many as five million acorns over its life.

Wildlife and timber

The Woodland Trust says oaks, sessile or pedunculate, support more wildlife than any other native tree, with more than 257 species of insect and a place for mosses, lichens, liverworts and nesting birds in the bark and deadwood. Acorns are eaten by jays, badgers and red squirrels, and the flower and leaf buds feed purple hairstreak caterpillars. EUFORGEN calls sessile oak one of the most economically and ecologically important tree species in Europe, valued for strong, durable wood used in construction, furniture and barrels, and for firewood and charcoal from coppice. Forest Research gives yield classes for oak of 2 to 8, with an average around 4, and rotations of 130 to 160 years, with sawlogs as early as 100 years under specific management.

Pests and diseases the sources name

Forest Research says sessile and pedunculate oak are relatively free of pests and diseases. It records oak mildew, a white powder on young leaves in warm humid weather that it does not think has a lasting effect, and defoliation by gypsy moth, oak leaf roller moth and winter moth that generally causes no long term health problems. It also names occasional, sometimes acute damage by the grey squirrel. Two entries are reportable through TreeAlert, as the same entry states: oak processionary moth, a notifiable defoliator it considers primarily a threat to human health, and acute oak decline, an emerging disease of mature oaks seen as weeping patches or stem bleeds, often with D-shaped exit holes of the two-spotted oak buprestid beetle.

Text on Forest Research is adapted from its tree species database entry and contains public sector information licensed under the Open Government Licence v3.0.