Whether we know it or not, most of us are familiar with the genus Vaccinium as it has among its members several current or potential commercial crops, such as blueberry, cranberry, bilberry and huckleberry. Vaccinium delavayi, however, is strictly ornamental and very unlikely to be our next export success.
The name vaccinium is an ancient one taken directly from the Latin vernacular: it was used to refer to Vaccinium myrtillus, the delightfully named whortleberry. Vaccinium delavayi takes its specific name, like so many Chinese plants, from the French Jesuit missionary Abb? Jean Marie Delavay (1838-95), who discovered the plant and introduced it to cultivation. He was also responsible for such well-known plants as Abies delavayi, Magnolia delavayi and Osmanthus delavayi reaching our gardens.
Vaccinium delavayi, a native of Burma and south-west China, is a hardy evergreen shrub with small, rounded leaves that are tough and leathery. In spring it produces clusters of small, bell-shaped to almost globular, white flowers that open from pink buds. The flowers are very much in the style of Pieris, Gaultheria, Andromeda and several other closely related genera in the erica family.
Pretty as the flowers are, the real appeal of this little blueberry lies in the deep bluish-black berries that follow. They are just like small blueberries and have a similar flavour but are rather acidic unless very ripe. Although it seems a shame to pick the berries, you might as well because the birds will have no such reservations.
While scarcely a spectacular plant, Vaccinium delavayi is attractive throughout the year and is always interesting, whether in flower, fruit or just as a neat foliage plant. It is an ideal specimen for a rockery or partially shaded corner. It grows to about 45cm high ? 60cm wide and can be kept trimmed to a small mound. However, any pruning will adversely affect either the flowering or fruiting.
As any blueberry grower will tell you, Vaccinium plants prefer acidic soil conditions. The small ornamental species are most at home when grown with other erica family plants such as dwarf rhododendrons, evergreen azaleas, ericas, callunas and pieris.
The native New Zealand Gaultheria species are interesting plants to combine with Vaccinium delavayi. Gaultheria crassa, in particular, looks very like its Chinese relative and provides a good illustration of how plants that evolve under similar conditions often resemble each other despite occurring thousands of kilometres apart.
Other small native berrying plants, especially those of the epacris family, also make good companions. An alpine rockery with good berrying forms of Pentachondra pumila, Leucopogon fraseri, Cyathodes empetrifolia, Gaultheria crassa and Vaccinium delavayi would be full of interest and colour throughout the year.
You won't find Vaccinium delavayi in every garden centre, but it shouldn't require too much of a search to locate a specimen. Try looking in the perennials as well as among the shrubs, as it's often sold at a very small size and tends to get lumped in with the rockery perennials.