Oriental hornbeam

How to recognise it

Habit

Small tree of 5–10 m or, often in the wild, a dense shrub of 2–5 m, with a rounded crown and fine, dense branching.

Leaf

Alternate, oval with a pointed tip, 3–5 cm, sharply double-toothed, with 12–16 pairs of parallel veins; glossy dark green, yellow to orange-brown in autumn.

Flower

Male and female catkins on the same tree, wind-pollinated: in April–May, as the leaves open, hanging male catkins of 2–5 cm and small green female catkins at the shoot tips.

Fruit

Small nuts of 3–4 mm, each with an oval, toothed, unlobed bract of 1.5–2.5 cm, in hanging clusters of 3–6 cm. Ripe in September–October.

Bark

Grey and smooth; older trunks, as in common hornbeam, often have ridges and grooves.

Look-alikes

Common hornbeam has larger leaves (5–10 cm) and nuts with a three-lobed bract of 3–4 cm. Hop-hornbeam (Ostrya carpinifolia) has fruits in papery bladders that together look like a hop cone.

Flowering: April–May · Pruning: February and August

Why grow it?

• A dense, fine-leaved hedge that takes clipping well and tolerates drought and lime better than common hornbeam.
• A dense hedge gives shelter and nesting places to blackbirds, dunnocks and other songbirds.
• The small nuts are food in autumn and winter for seed-eating birds such as the hawfinch.
• Stays small: suitable for a small garden, as a multi-stemmed shrub or small tree.
• Graceful, hanging fruit clusters in summer and yellow to orange-brown autumn colour.
• Popular with bonsai growers for its small leaves and fine branching.

Oriental hornbeam: where does it grow best?

• In the wild on dry, warm slopes, often on limestone, in open oak woods, on woodland edges and in low, dense scrub, up into the mountains.
• In the garden: full sun to partial shade; it also tolerates quite a lot of shade, but grows more open there.
• Any well-drained soil, from sand to loam, preferably chalky; dry soil is no problem, wet soil is.
• As a free-standing tree or shrub, allow 3–5 m of space; for a hedge, 3–4 plants per metre.

Goes well with

• Smoke bush: Grows with the Oriental hornbeam in the Balkans and turns fiery red in autumn.
• Common lilac: Another plant of Balkan scrub, with fragrant flowers in May for bees and butterflies.
• Cornelian cherry: Small yellow flowers in February–March for the first bees, and red fruits for birds.
• Lesser periwinkle: An evergreen ground cover with blue flowers for the shady side at the foot of the hedge.

Oriental hornbeam: when and how to plant it?

1. Buy young plants in containers or bare-root from a tree nursery; for a hedge, plants of 60–100 cm are ideal.
2. Plant bare-root stock from November to March, when the soil is neither frozen nor waterlogged.
3. For a hedge, dig a trench 40 cm wide and deep, loosen the bottom and set the plants at the same depth as before.
4. Firm the soil well, water generously straight away and spread a mulch of leaf mould or wood chips.
5. After planting, cut a new hedge back by a third: this makes it branch from the bottom.
6. Never dig up plants in the wild: buy them from a nursery.

Care

Watering

For the first two summers, water generously every week in dry spells. After that it tolerates drought well.

Feeding

Not needed. Leave the fallen leaves under the hedge; they turn into humus on their own.

Hedge clipping

Once or twice a year. Keep the hedge wider at the bottom than at the top, so that light reaches every part.

Mulching

A layer of leaf mould around young plants keeps the soil cool and moist.

Shape

For a single-trunk tree, gradually remove the lowest branches and the shoots at the base during the first years.

Tip: If you want a hornbeam hedge for a dry, chalky or warm spot, Oriental hornbeam is a better choice than common hornbeam. Thanks to its small leaves, a clipped hedge also keeps a fine, neat look.

Pruning and mowing

Pruning months: February and August.

When: Clip a hedge in late August, after the nesting season, and lightly again in February if needed. Prune a free-standing tree in February, before it comes into leaf.

How:

• Clip a hedge with shears into a slight trapezium: wider at the bottom than at the top.
• On a tree or shrub, remove dead, broken and crossing branches, just outside the swollen collar at the base of the branch.
• It regrows well from old wood: a bare or overgrown hedge can be cut back hard in February.
• Rejuvenate a multi-stemmed shrub by sawing one of the oldest stems off at ground level every few years.

Caution: Before clipping a hedge, always check that no birds are nesting. Do not prune in March–April, when the sap starts to rise.

Pruning: when and how · Pruning calendar and basic rules

Propagation

Seed

Pick the fruit clusters in September–October, when the bracts turn brown, and sow the nuts straight away outdoors in a tray. They need one or two winters to germinate.

Cuttings

Softwood cuttings in June, in moist cutting compost under plastic. This does not always work; for a hedge it is better to buy young plants.

Oriental hornbeam: how does it get through the winter?

Hardy to −25 °C.

• Deciduous: the leaves turn yellow to orange-brown in October and fall.
• Hardy to about −25 °C: it needs no protection in a Belgian winter.
• In winter the fine, dense branching remains good cover for small birds.
• Leave the fallen leaves under the hedge: hedgehogs, beetles and spiders spend the winter in them.

Diseases and pests

• Drought in young plants: In the first year, young hedging plants dry out quickly. Water generously and mulch the soil.
• Bare base: A hedge that is wider at the top than at the bottom goes bare at the base. Clip it into a trapezium.
• Root rot: In wet, compacted soil the roots die and the plant wilts. Only plant in well-drained soil.
• Aphids: Sticky young shoots in May–June. Ladybirds and tits usually sort it out.

Through the year

• February: Prune a free-standing tree. Lightly tidy the hedge or cut back a bare hedge.
• March: Bare-root planting is still possible. Mulch.
• April: Leaves open and the catkins flower.
• May: End of flowering. Water young plants in dry spells.
• June: Take softwood cuttings. The fruit clusters are growing.
• August: In late August, clip the hedge, after the nesting season.
• September: The fruit clusters turn brown: collect seed and sow straight away.
• October: Yellow to orange-brown autumn colour.
• November: Leaf fall. Plant bare-root stock.
• December: Rest. Plant as long as it is not freezing.

Did you know?

• The name hornbeam comes from Old English: horn for the very hard wood and beam, the old word for tree. Hornbeams are not related to beech but belong to the birch family, together with hazel.
• On dry, chalky slopes in the Balkans it forms a low, dense scrub with smoke bush, lilac and other shrubs, known in the Balkan languages as shibljak.
• Bonsai growers value it for its small leaves and fine branching: it is one of the classic species for bonsai.