# Sessile oak (Quercus petraea)

> The oak of hilly, wetter western and northern Britain and Ireland, growing 20 to 40 m with a straighter trunk than English oak and stalkless acorns. It is the national tree of Ireland and the dominant tree of Atlantic oakwoods. Like English oak it supports hundreds of insect species, so it is a mainstay of upland native woodland planting.

Source: https://treerm.org/trees/quercus-petraea · Updated 2026-11-08 · License CC BY 4.0

## Facts

- Also called: Durmast oak, Irish oak
- Family: Fagaceae
- Type: Broadleaf, loses its leaves in winter
- Mature height: 30 m; spread 22 m
- Growth: Slow growing; lives about 500 years
- USDA hardiness zones: 4 to 7
- Light: Full sun
- Water: Moderate water
- Soil: Well-drained, often acidic and stony upland soils; tolerates poorer, drier ground than English oak
- Native range: Native across most of Europe including Britain and Ireland, east to Ukraine, the Caucasus, northern Iran and Türkiye.

**Benefits:** Shade, Wildlife, Birds, Pollinators, Long lived, Stores carbon well, Storm resistant

**Good for:** parks, Timber, Reforestation, Yard shade

**Watch out for:** Large roots, Heavy litter

## Care

Plant small bare-root trees in winter with tree guards; water through the first two summers on dry sites. Prune lightly in late winter if at all. Threats are acute and chronic oak decline, and oak processionary moth where present in south-east England.

## Where it stands

- **Native:** Germany; France; ENG, United Kingdom; NIR, United Kingdom; SCT, United Kingdom; WLS, United Kingdom; Ireland (National tree of Ireland)

## Sources

- https://www.woodlandtrust.org.uk/trees-woods-and-wildlife/british-trees/a-z-of-british-trees/sessile-oak/
- https://www.gbif.org/species/2880130
- https://plants.ces.ncsu.edu/plants/quercus-petraea/