Quercus petraea - Sessile Oak

The Sessile Oak is a British native tree, originally found more in the north and the west of Britain, whereas the English Oak favoured the south and the east. Also known as the Durmast Oak, it is often considered to be a better-shaped tree than its near relative, with a longer, straighter trunk, slightly narrower shape and more handsome leaves. It is its equal in conservation value, and has a faster growth rate.

Site and soil

Most soils except shallow, poorly drained sites. Will do well on exposed sites and in coastal areas.

Height and spread

Below are the approximate stages of growth, assuming sited in suitable conditions for this species;

After 10 years: 6m x 3m
After 20 years: 12m x 8m

Leaf and bark

The leaves are less deeply lobed than those of the common oak, and with a distinctive yellow stalk. They are 7.5 – 12.5cm and dark green, turning brown before leaf fall in autumn. The bark is greyish, with deep fissures and cracks.

Flower, seed and fruit

The yellow-green male catkins and insignificant female flowers appear in May. The smooth glossy green seeds (acorns) are held in rough-textured cups and ripen to brown in autumn. They are produced without stalks.

Uses

Woodland, parkland, specimen tree, commemorative tree.

The very hard, strong, durable wood is used for shipbuilding, furniture, buildings and cabinet-making. The bark has been used for tanning and for medicinal purposes. Oak sawdust and oak galls were used to make dyes and ink. The acorns were a valuable food for pigs – and for humans in times of famine. The oak was revered by the ancient Druids, and is still a focus for folk customs and superstition in many areas.

Mistletoe grown on oak was thought to have the most magical powers. Many English place names are derived from the oak, for example Okehampton and Sevenoaks.

Wildlife

Over 400 different species of insects rely on the oak, making it very valuable in conservation terms. Jays and small mammals eat the acorns, and Pied Flycatchers breed amongst its branches. Because the oak is late into leaf, wildflowers and mosses thrive beneath its branches. The Sessile Oak reaches a great age – up to 700 years – and as it ages the trunk tends to become hollow, offering shelter for animals, insects and birds.