Carpinus

Carpinus is the botanical name for a group of hardy, deciduous (leaf-losing) trees or large shrubs native to Europe, the Himalayas, eastern Asia, and North and Central America. The common names of these trees include Hornbeam, Blue Beech, Water Beech, and Ironwood. These trees range in height from 15 to 80 feet. C. caroliniana grows from 20 to 40 feet high. It has simple leaves arranged alternately on the twigs. They are rounded at the base and taper off into a pointed tip; they grow from 2 to 4 inches long. They are smooth and thin, but strong, dark green above and paler beneath. The edges are finely double toothed. They turn scarlet or bright orange in the fall. Male and female flowers are produced separately, but both grow on the same tree. The male catkins hang from the branches and are greenish-yellow. The female catkins are erect and shorter at first, but they gradually elongate and droop. The nut-like fruits are enclosed in the bases of 3-lobed, leaf-like bracts and are produced in pairs in loose, pendulous clusters.
They ripen in the fall. This tree forms a nice bushy head. C. cordata, a native of Japan, Asia, and northern China, grows 30 to 40 feet high. This tree has large, heart-shaped leaves. Its variety chinensis has smaller leaves and hairy young shoots. The wood of these trees is used in the manufacture of agricultural implements.

Pot Cultivation

Hornbeams grow quickly when planted in well-cultivated ground; otherwise, they develop slowly. These trees will flourish on deep, moist loam, but will grow in any soil, including soil formed on limestone. Plant them in an open, sunny place. These trees may be pruned in August or in the fall after the leaves have fallen. This consists of thinning the branches of young trees when too many are growing from the main trunk, and thinning or shortening the branches near the tops of young trees so that each tree has a single and straight leading shoot.

Propagation

Seeds may be sown when ripe in the autumn, in a cold frame or a sheltered border outdoors. Seedlings sprout irregularly, sometimes not producing plants until the second year. The lower branches may be layered in the spring; or, when increasing rare kinds, grafting on seedlings may be done.

C. cordata	C. laxiflora

VARIETIES

• C. Betulus, European Hornbeam;
• C. caroliniana, American Hornbeam;
• C. cordata;
• C. laxiflora;
• C. Tschonoskii.