Carpinus
Large, deciduous, graceful trees or bushy shrubs with attractive foliage and hop-like fruit clusters in late summer/autumn. Commonly used for dense hedging.
Family: Betulaceae (birch family)
Botanical Name: Carpinus
Common Names: Hornbeam, charmille, horn
beech, horse beech, yoke elm
Foliage: Deciduous, ovate, deeply ribbed, toothed green leaves. Turning yellow in autumn. Handsome grey, fluted bark.
Blossom: Short green catkins, followed by open fruiting clusters of winged nutlets.
Flowering Period: Late spring.
Soil: Moist but well-drained soil (chalk, clay, sand or loam). Acid, alkaline or neutral pH.
Conditions: Full sun or partial shade in any aspect.
Habit: Bushy.
Type: Tree or large shrub.
Origin: Europe, North America, Japan and China.
Hardiness: Fully hardy in the UK.
Planting and Growing Carpinus
Hornbeams thrive in fertile, well-drained soil, in full sun or partial shade. Although they will also grow well in most ordinary soil types, including chalk and wet, sticky soils.
Ideal for woodland settings. Can be grown as a tall dense hedge (planted 18in (45cm) apart).
Taking Care of Carpinus
Like beach, hornbeam retains its autumn leaves until the following spring.
Pruning Carpinus
Pruning of trees is not necessary except for the removal or any dead or damaged branches. Trim hedges in July or August.
Pests and Diseases
Susceptible to attack by caterpillars and aphids. Can be affected by powdery mildews, coral spot and honey fungus.
Propagating Carpinus
Can be propagated from seed sown in spring or by softwood cuttings or grafting.
Varieties of Carpinus
Carpinus betulus (common hornbeam) is a large deciduous tree with a grey fluted trunk. It has distinctive ribbed, green leaves that fade to yellow in autumn. Short flowering catkins appear in spring, followed by open fruiting catkins. Can be used for dense hedging. Eventual height 40 to 80ft (12-24m). Hedges to around 20ft (6m). Variety 'Fasligiala' is a more compact pyramidal form. The shorter form 'columnaris' is an elegant compact slender variety and 'incisa' has narrow deeply toothed leaves. The popular variety 'pendula' has attractive pendulous branches.
Carpinus caroliniana (American Hornbeam) forms a large handsome tree, that is shrubby and rounded to spreading in habit. The autumn leaves are yellow or orange. Green fruit clusters hang beneath the branches in summer, turning yellow-brown. Height to 40ft (12m).
Carpinus cordata is a slow-growing tree, native to Japan. The variety 'chinensis' with smaller leaves was introduced from China in 1901. Height to 40ft (12m).
Carpinus japonica (Japanese hornbeam) has more oblong, narrower leaves and bears large crops of pendulous fruit clusters. Height to 50ft (15m).