Sourcing Methods and Cultivation Techniques for Chinese Hackberry Bonsai

  The Chinese hackberry (Celtis sinensis) has an elegantly antique and unrestrained posture, with rough, mottled bark that does not crack, a tall and straight trunk, and gracefully spreading branches. In spring, new leaves first emerge, covering the branches in tender green; in autumn, the foliage turns deep yellow, making it highly ornamental. In winter, when the leaves have almost entirely fallen, it can be appreciated as a bare tree. Taking its old stumps, with exposed roots and bent trunks, gnarled and antique, green leaves trailing along the branches, layered and towering in verdant beauty, it is richly evocative of wild mountain forests. The Chinese hackberry is a deciduous tree of the order Rosales (Urticales), distributed across Henan, Shandong, the middle and lower reaches of the Yangtze River and the provinces to its south, as well as Taiwan, China; it is also found in Vietnam and Laos. This tree is often cultivated as a bonsai.

  The bark of the Chinese hackberry is smooth and gray. Its external features are alternate leaves, long petioles, and leathery blades that are broadly ovate to narrowly ovate, with tips acute to acuminate, bases rounded or broadly cuneate and oblique, shallow serrations along the margin above the middle, and three main veins; the upper surface is hairless, while the lower surface has sparse hairs along the veins and in the vein axils. The Chinese hackberry is mainly obtained as a bonsai plant through artificial propagation and collection from the wild.

  Artificial propagation:

  The Chinese hackberry is usually propagated by sowing seeds. The seeds mature from September to October, and the fruit turns reddish-brown. They should be harvested promptly, spread out in the shade to dry, cleaned of debris, and stored mixed with sandy soil. Sowing takes place in March of the following spring. Before sowing, the seeds must be treated by cracking the seed shell with a wooden stick or scarifying the outer seed coat with sand; only then can they be sown, which helps the seeds germinate.

  The seedbed soil should preferably be loose, fertile, well-drained sandy loam. After sowing, cover with a layer of fine soil about 2 cm thick, then cover with rice straw and water thoroughly once. Germination begins after about 10 days, and once the seedlings emerge, remove the straw promptly.

  During the seedling stage, good maintenance and management must be carried out, with attention to loosening the soil, weeding, topdressing, and appropriate thinning. Seedlings can reach 30-40 cm in height in the first year. Young trees intended for cultivating Chinese hackberry bonsai should be pruned and shaped with attention: suppress the leader to promote side growth, control the height growth of the sapling, and encourage the trunk to thicken and side branches to grow, so as to facilitate potting and shaping.

  Collection from the wild:

  The Chinese hackberry is commonly found growing wild along streams and valleys in the hilly low mountains of the Yangtze River basin and regions to its south. Old, repeatedly cut stumps with curious, antique forms that have sprouted can be collected and grown on for root development.

  After pruning to promote root development and the sprouting of new branches, the tree is then shaped and cultivated. After 1-2 years, it is potted and worked on, making it possible to produce a rugged, antique Chinese hackberry bonsai in a relatively short period.