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Broadleaf tree · Beech family (Fagaceae)
Turkey oak
Quercus cerris
Turkey oak is a fast-growing oak of 25–35 m from southern and south-eastern Europe and Turkey, long planted here in parks and avenues. You recognise it by its narrow, irregularly lobed leaf, the long threads around the buds and the ‘shaggy’ cup of its acorns. It tolerates drought and chalk better than our native oaks, but it is less rich in wildlife than English oak and sessile oak. With a crown about 15 m across it is too big for an ordinary garden: plant it only in a park, an avenue or a very large garden.
Caution: In large amounts, acorns and young leaves are poisonous to horses and cattle. In summer the oak processionary moth can spread irritating hairs on Turkey oak too: avoid contact with the nests.
Light
Full sun
warm and bright
Moisture
Dry
tolerates drought
Legal basis
Any garden soil
any pH
Hardiness
Throughout Belgium
no protection needed
Size
25–35 m
tall
Flowering
May
| Pruning months | July–August and November–February |
|---|---|
| Height | 25–35 m |
| Native to Belgium | No, planted |
| Poisonous to people and pets | In part: see Caution above |
| Flowering | May |
Identify
Turkey oak: how do you recognise it?
- Habit
- Large tree of 25–35 m with a straight trunk and a broad, domed crown about 15 m across.
- Leaf
- Alternate, 6–12 cm, oblong with 4–8 pairs of pointed, irregular lobes; upper side somewhat rough, underside greyish-hairy. Long, thread-like stipules surround the buds.
- Bark
- Dark grey and deeply furrowed into long plates; orange-brown in the furrows.
- Flower
- Hanging yellow catkins in May, with the young leaves.
- Fruit
- Acorns in a cup covered with long, curly, moss-like scales; they ripen only in their second year.
- Difference from English oak
- English oak has a leaf with rounded lobes and ear lobes, no threads round the buds, and a smooth cup.
- Difference from red oak
- Red oak has a much larger leaf with bristle-tipped lobes, and bark that stays smooth for a long time.
Flowering: May · Pruning: July–August and November–February
Identify by feature: Lobed leaves (like an oak) · Nuts, acorns and chestnuts
Looks like it, but isn’t
- English oak Quercus robur: leaf with rounded lobes and ear lobes, no threads round the buds, and a smooth cup. Difference from English oak
- Red oak Quercus rubra: much larger leaf with bristle-tipped lobes, and bark that stays smooth for a long time. Difference from red oak
In your garden
Why grow it?
- Grows fast and becomes a stately park tree.
- Copes with drought, chalk and urban conditions better than our native oaks.
- Handsome, deeply furrowed bark with orange-brown fissures.
- Finely cut leaves and acorns with a striking ‘shaggy’ cup.
Turkey oak: where does it grow best?
- Full sun.
- Almost any soil, preferably free-draining: dry sand and chalky soil too.
- Copes well with drought, heat and wind.
- Allow for 25–35 m in height and a crown about 15 m across: only for a park, an avenue or a very large garden, well away from buildings.
- Light
- Full sun
- Legal basis
- Any garden soil
- Moisture
- Dry
- Size
- 30 m tall, 15 m wide
- Hardiness
- Throughout Belgium, no protection needed
Goes well with
- Field maple: A native small tree that, like Turkey oak, tolerates drought and chalk; attractive at the edge of the crown.
- Holly: An evergreen native shrub for the partial shade under large trees.
- Common ivy: Evergreen ground cover for the dry shade under the crown.
Good and bad companions
Goes well with
- Like the acid soil under this tree: heather, rhododendron, japanese skimmia, raspberry, highbush blueberry, witch hazel, broom, gorse
- Tolerate the shade under this tree: oregon grape, rhododendron, oleaster, japanese skimmia, garden privet, camellia, laurustinus, box-leaved honeysuckle
Maintenance
Turkey oak: when and how to plant it?
- Plant from November to March when the ground isn’t frozen; a young tree establishes best.
- Dig a generous planting hole and don’t bend the taproot.
- Put a stake on the windward side and tie the trunk loosely; remove stake and tie after 2–3 years.
- Water generously after planting and during dry spells in the first year.
Care
- Watering
- In dry spells during the first two years; after that it copes, even in dry summers.
- Feeding
- Not needed. Leave the fallen leaves under the tree: they turn into humus.
- Formative pruning
- Train a young tree to a single trunk and a strong crown; little pruning is needed later.
- Oak processionary moth
- Turkey oak can get nests too: from May to July, check the trunk and thick branches, especially near a path or play area.
Tip: If you want an oak for wildlife, plant a native English oak or sessile oak instead: they support far more insects and birds. Turkey oak is mainly a choice for dry, chalky soil or an urban spot where our oaks struggle.
Turkey oak: when to prune it?
Pruning months: July–August and November–February.
When: Dead, diseased and broken branches can be removed at any time of year. Formative pruning in winter or summer.
How:
- Prune mainly when young to form a strong crown; little after that.
- On a young tree, choose a single leader and gradually remove competing leaders and branches that hang too low.
- Cut large branches in three steps, just outside the branch collar.
Caution: Do you see nests of the oak processionary moth? Don’t prune yourself but have them removed by a professional.
Propagation
- Sowing
- The acorns ripen only in their second autumn. Sow them fresh, in October, 3–5 cm deep in a pot or where they are to grow, and don’t let them dry out.
Turkey oak: how does it get through the winter?
Hardy throughout Belgium: no protection needed.
- Fully hardy.
- In winter you recognise it by the buds with long, curly threads (the stipules) and by the deeply furrowed bark with orange-brown fissures.
Diseases and pests
- Oak processionary moth: Caterpillars in groups with irritating hairs, in nests on the trunk and branches (May–July). Don’t touch them; have the nests removed by a professional.
- Oak powdery mildew: White fungal coating on young leaves, especially on the second flush in summer. Harmless to an older tree.
- Knopper galls: Not on Turkey oak itself: the gall wasp it hosts turns the acorns of nearby English oaks into sticky knopper galls.
- Large branches: Have an old tree near paths or buildings checked by an arborist every few years.
Through the year
- January: Remove dead and broken branches; winter formative pruning.
- February: Last month for winter formative pruning and for planting.
- April: Leaves breaking: don’t prune.
- May: Flowering (catkins); watch for oak processionary moth nests.
- July: Summer pruning of young trees; keep watching for processionary caterpillars.
- August: Summer pruning still possible; water young trees in dry spells.
- October: Gather ripe acorns for sowing.
- November: Planting season starts; winter formative pruning possible.
- December: Remove dead branches; winter formative pruning.
Use
What can you use it for?
- Garden and landscape
- Fast-growing park tree that tolerates drought and chalk well.
- Wood
- The wood splits and moves a lot; it is used mainly as firewood.
- For wildlife
- Essential for the knopper gall wasp; otherwise less rich in insects than our native oaks.
You and this species
Did you know?
- No Turkey oak, no knopper galls: the gall wasp that deforms the acorns of English oak needs the catkins of Turkey oak for its second generation.
- Its Dutch name, ‘moss oak’, refers to the cup with long, curly scales, which looks as if it were overgrown with moss.
- Crosses between Turkey oak and cork oak are called Lucombe oak (Quercus × hispanica): semi-evergreen trees with a thin layer of cork, sometimes seen in parks.