Carpinus turczaninovii Seeds | Turczaninov’s Hornbeam

Small toothed hornbeam leaves and hanging bracted nutlets on a compact branch — Turczaninov’s Hornbeam (*Carpinus turczaninovii*): Betulaceae, dry rocky hillsides of northern China, Korea and Mongolia.

LATIN NAME: Carpinus turczaninovii

COMMON NAME: Turczaninov’s Hornbeam

Plant Profile

Turczaninov’s hornbeam is the Chinese hornbeam that behaves like a large shrub, and in a small garden that is its recommendation. It grows five to ten metres, often with several stems from the base, and the crown is dense, rounded and fine-textured, built from small ovate leaves with sharply toothed edges and prominent parallel veins. The leaves turn butter yellow in autumn and hold late. Catkins appear in spring with the foliage, and the fruit hangs in loose clusters of nutlets, each with a three-lobed bract that acts as a wing. The bark is smooth and grey, and on old plants it becomes slightly fluted. It comes from northern China, Korea and Mongolia, on dry rocky hillsides and limestone slopes, which explains its tolerance of drought and hard frost. It is one of the hornbeams most used for bonsai in China and Japan.

Science & Biotechnology

Carpinus turczaninovii is a diploid, 2n = 32, and it sits close to C. cordata and C. fargesii in the Chinese hornbeams, from which it differs in the small leaves, the compact habit and the shape of the fruit bract. Its natural habitat is the dry, calcareous hillside, and it shows the anatomy that goes with it: small leaves with thick cuticles, sunken stomata and a deep, wide root system that lets it survive both drought and frost. The species is andromonoecious, with male and female catkins on the same tree, and it is wind-pollinated. Seed has the usual carpinus double dormancy, and natural regeneration is sporadic, which is one reason it is less common in the wild than its range suggests. It is also one of the hornbeams most used in bonsai, and the trade in selected forms is larger than the trade in timber.

Uses & Benefits

It is a garden tree for small spaces: a lawn specimen, a dense screen, a subject for a large pot, and above all a bonsai subject, where the small leaves, the fine branching and the tolerance of root pruning make it one of the easiest deciduous trees to train. In northern China it is planted on dry rocky slopes and used in shelterbelts, since it establishes on thin soil and holds it. The wood is hard and pale and goes into tool handles and small turnery, though the tree is rarely large enough to be a timber crop. It has no medicinal standing beyond a local astringent use of the bark. Its autumn colour and its late leaf retention make it a better garden plant than its obscurity would suggest.

Growing from Seed

Sow in autumn and leave the pots outside for two winters, or give three months of warm followed by three of cold. Germination is slow and uneven, and the seed is often only partly viable, so sow thickly. Use a gritty, lime-rich mix with good drainage, and keep the seedlings in full sun. Pot on when they are ten centimetres, and do not overfeed, because rich compost produces coarse growth and weak wood. Plant out at thirty to fifty centimetres, in full sun and well-drained soil, and water only for the first two summers. For bonsai, start root pruning in the second year and repot every two to three years. It tolerates hard pruning and back-buds reliably on old wood.

Our Take

A compact, tough hornbeam for a small garden or a bonsai pot, with good autumn colour and no special demands. Give it sun, drainage and a hard cut now and then.

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