Cornus hongkongensis Seeds | Hong Kong Dogwood
LATIN NAME: Cornus hongkongensis
COMMON NAME: Hong Kong Dogwood
Plant Profile
Cornus hongkongensis is the evergreen dogwood of southern China, and it flowers in spring with the new leaves rather than before them. The flower heads are flat clusters of small greenish flowers surrounded by four large, creamy-white bracts, and they open in April on a tree that has kept its leaves all winter. The foliage is leathery, glossy and dark, turning red and purple before it falls in late spring, just as the new growth pushes.
The tree grows to about ten metres in warm woodland from Hong Kong and Guangdong west to Yunnan and into Vietnam. It has been cultivated in southern Chinese gardens for a long time, and it is one of the few dogwoods that will grow in a subtropical climate, which is why it is planted in Hong Kong and in Guangzhou parks.
Science & Biotechnology
The white bracts are not petals. They are modified leaves that surround the true flowers, which are small and green in the centre of the cluster, and their job is to attract pollinators to a flower head that would otherwise be invisible. The same arrangement occurs in the flowering dogwood of North America, and the two are placed in the same section of the genus.
The genus is divided between species that flower before the leaves and those that flower with them, and the difference is a matter of climate. In a warm, frost-free climate there is no advantage in flowering early, so the evergreen species flower with the new growth. The fruit is a small red drupe that ripens in autumn and is eaten by birds, which disperse the seed.
Uses & Benefits
The tree is grown as an ornamental for the spring bracts and the evergreen foliage, and it is planted in parks and in gardens in southern China. The wood is hard and close-grained and is used for small tools and for turnery, though the trees are too small for timber.
In Chinese medicine the bark and the fruit are used as a tonic and as a treatment for diarrhoea, and the leaf is applied to wounds. The fruit is edible but sour and thin-fleshed, and it is not gathered commercially. The tree is not a crop, and its value is ornamental and cultural.
Growing from Seed
Seed should be sown fresh, since it has a deep dormancy. Clean it from the fruit, sow it in a moist, peaty mix, and leave the pot outdoors for a year; germination may come in the second spring. Cuttings of half-ripe wood in summer are slow but more reliable for a named form.
The tree wants light shade and a deep, moist, acid soil, and it resents drought and lime. It is hardy to about minus eight, which makes it a tree for mild climates only. Plant it in a sheltered spot with leaf mould, water it through dry summers, and avoid disturbing the roots, which are shallow.
Our Take
A dogwood for mild, damp gardens, flowering with the new leaves and holding its foliage through winter. Best in shade with leaf mould.
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