Buxus sinica Seeds | Chinese Boxwood
LATIN NAME: Buxus sinica
COMMON NAME: Chinese Boxwood
Plant Profile
Chinese boxwood is a slow-growing evergreen shrub or small tree, one to six metres tall in the wild, with small, opposite, glossy leaves and square, yellow-green shoots. The flowers are insignificant, greenish and hidden among the leaves in spring, and they smell faintly of honey.
The plant is native to China and Korea, where it grows in thickets and on cliffs, and it has been shaped in Chinese gardens for more than a thousand years. Its wood is extremely dense and fine-grained, and it has been used for carving, for printing blocks and for the pegs of musical instruments. It is very close to the European Buxus sempervirens and is treated by some authors as a subspecies of it.
Science & Biotechnology
The Chinese boxwoods were separated from Buxus sempervirens largely on leaf and capsule characters, and the group has since been revised several times: what was called Buxus microphylla in Chinese gardens is now often placed in B. sinica, and the names in the nursery trade are a muddle. Molecular work has confirmed that the Asian and European boxwoods form a single complex that spread across Eurasia, with little genetic distance between the forms.
The wood’s density comes from the extreme shortness of the tracheids and the thickness of the cell walls, which is why box sinks in water and why it takes a polish without any finish. The genus contains steroidal alkaloids, and the bark and leaves are toxic to livestock. The slow growth that makes the wood so fine is also what makes the plant expensive to raise to a useful size.
Uses & Benefits
Chinese boxwood is used for the same purposes as its European relative: low hedges, topiary, parterres and bonsai. Its slow growth is an advantage in a clipped garden, since a hedge holds its shape for a year, and a disadvantage for anyone wanting a quick screen. In China it is a classic subject for penjing, and old specimens are trained over decades into clouds of foliage on bare trunks.
The wood is prized by carvers and by makers of woodwind instruments, and it is also used for the blocks from which Chinese woodblock prints were cut. Two problems now dominate its cultivation: box blight, a fungal disease that strips the foliage in wet summers, and the box tree moth, whose caterpillars can defoliate a hedge in a few weeks. Both are reasons to buy from a nursery that propagates its own stock.
Growing from Seed
Box seed is small and short-lived, and it should be sown as soon as it is ripe in autumn. Sow on the surface of a loam and grit mix, cover with three millimetres of sieved compost, and leave the pan in a cold frame; germination is slow and uneven and can take two seasons. The seedlings are tiny for the first year and need shade and steady moisture.
Pot them on into deep pots, since box makes a long taproot, and grow them on for three or four years before planting out. Plant in autumn or spring, in any soil that drains, in sun or shade, and water through the first two summers. Clip hedges in late spring and again in late summer, and clear the clippings from the crown of the hedge, because they harbour blight.
Our Take
The finest wood and the tightest hedge in the genus, but a slow plant that now needs watching for blight and moth.
Related Reading
Gardeners who grow Chinese Boxwood often pair it with these related subjects: