Side by side
English oak or sessile oak? How to tell them apart
Quercus robur · Quercus petraea
You can tell an English oak by its acorns on long stalks and its leaves on very short stalks with two small ear-like lobes at the base; in the sessile oak it is the other way round: acorns without stalks and leaves on a proper stalk.
Look at the stalks. The English oak has its stalk on the acorns (3–8 cm) and almost none on the leaf; the sessile oak has a leaf stalk of 1–2.5 cm and acorns sitting directly on the twig. Its leaf is also more evenly lobed, with a wedge-shaped base and no ear-like lobes.
| English oak | Sessile oak | |
|---|---|---|
| Leaves | Alternate, 7–14 cm, with 4–7 pairs of rounded lobes. Leaf stalk very short (under 1 cm); the leaf base has two small ear lobes. | Alternate, 7–14 cm, regularly lobed with 5–8 pairs of shallow lobes. Leaf stalk 1–2.5 cm; leaf base wedge-shaped, without ear lobes. |
| Flowering | April–May | May |
| Fruit | Acorns in 1–3s on a long stalk (3–8 cm). | Acorns in clusters, (almost) without a stalk, sitting directly on the twig. |
| Bark | Grey and deeply, coarsely fissured. | Grey, more finely and regularly fissured than in English oak. |
| Shape and height | Broadleaf tree, 25–40 m | Broadleaf tree, 20–40 m |
| Site | Full sun, any garden soil, normal | Full sun, acid soil, dry |
| Native to Belgium | Yes | Yes |
| Good for bees, butterflies and birds | Yes, for butterflies and birds | Yes, for butterflies and birds |
| Poisonous to people and pets | Not known to be poisonous | Not known to be poisonous |
| Pruning months | July–August and November–February | July–August and November–February |
The best feature in each season
- Spring
- Both come into leaf in April–May. The young leaves already show the difference: a very short stalk with ear-like lobes on the English oak, a proper stalk and a wedge-shaped base on the sessile oak.
- Summer
- Turn a branch over: on the English oak the young acorns hang from long stalks, on the sessile oak they sit in clusters against the twig. The leaf of the sessile oak is a more even green and flatter.
- Autumn
- The best time to look: pick up the acorns. If they hang from a long stalk, it is an English oak; if they sit stalkless in a little cluster, it is a sessile oak.
- Winter
- Without leaves, look at the buds and the bark. The sessile oak has slimmer, more pointed buds and more finely, evenly furrowed bark; the English oak is more coarsely furrowed. Fallen leaves under the tree help most of all.
Where do they grow?
Both are native. The English oak grows on almost any soil, including heavy clay and wet valleys: you see it in meadows, hedgerows and avenues all over Belgium and the Netherlands. The sessile oak prefers drier, acid soil and slopes; it is common in the Ardennes and on the higher sandy soils. Hybrids between the two are not unusual.
Which one for your garden?
- Both reach 20–40 m and are too big for an ordinary garden. In a large garden, a meadow, a hedgerow or a row of trees they are irreplaceable: no other tree here supports so much life.
- Choose the English oak on moist or heavy soil, the sessile oak on dry, acid sand or loam. Acorns and young leaves are poisonous to horses and cattle in large amounts: do not plant them in the middle of a horse paddock.
Did you know? The Latin names tell the story too: robur means strength, and petraea refers to the stony ground the sessile oak likes.
Read on
- Plant profile: English oak
- Plant profile: Sessile oak
- English oak: when and how to prune
- Sessile oak: when and how to prune
- Identification key: the question that separates them