A small group of medium-sized, deciduous trees with interesting hop-like fruits. Rarely grown in the UK. Closely related to Carpinus Betulus (hornbeam).
Botanical Name: Ostrya
Common Names: Hop-hornbeam, ironwood
Foliage: Deciduous, glossy, oval-shaped green leaves with toothed edges. Good yellow autumn colour. Finely cracked bark.
Blossom: Male (catkins) and female flowers appear on same plant in spring. Followed by Pendent clusters of pale yellowish green fruits in summer.
Flowering Period: Spring.
Soil: Moist but well-drained or well-drained soil (chalk, clay, sand or loam). Acid, alkaline or neutral pH.
Conditions: Full sun or part shade. Grow in any aspect, in a sheltered location.
Habit: Conical when young, broad-spreading when mature.
Origin: Southern Europe, West Asia.
Hardiness: Fully hardy in the UK.
Plant out saplings in the spring. Thrives in any good fertile, moist but well-drained soil, in full sun or partial shade.
Ideal specimen tree for a large garden.
Protect young trees from strong winds and bright sunlight.
Not necessary, except for removal of dead or damaged wood in early autumn.
Can be affected by oak bark beetle, chestnut blight and fungal canker.
Increase from seed or by hardwood cuttings. Sow seed in free draining compost outside in autumn. Seed may take 18 months to germinate.
Ostrya carpinifolia (Hop-hornbeam) is an upright, sun-loving, woodland tree with green hornbeam-like leaves and hanging hop-like fruits in summer. Height to 60ft (18m) or more.
Ostrya japonica (Japanese hop-hornbeam) has dark grey-brown bark and velvety young leaves. Height to 60ft (18m) or more.
Ostrya virginiana (American hop-hornbeam) is a long lived, slow-growing, small to medium sized tree. Hop like papery fruits in summer. Height to 40ft (12m) or more.