Buxus is a genus of about 70 species of which we are for bonsai purposes looking at just two, Buxus microphyllia and Buxus sempervirens, the majority of the others are sub-tropical and unlikely to survive European winters, severely damaged by severe frosts.
Buxus sempervirensThis is an evergreen shrub or small tree growing up to 1 to 9 m tall, with a trunk up to 20 centimetres in diameter Arranged in opposite pairs along the stems, the leaves are green to yellow-green, oval, 1.5 – 3 cm long, and 0.5 – 1.3 cm broad. The flowers are inconspicuous but highly scented, greenish-yellow, with no petals.
Buxus microphyllaThe Japanese box or little-leaf box, is a species of flowering plant in the box family found in Japan and Taiwan. It is a dwarf evergreen shrub or small tree growing to 1 m tall and wide. The bright green leaves are 10 – 25 millimetres long, oval with a rounded tip.
Both genuses are frequently plagued by Box moth and caterpillar, which can completely decimate plants. Also a problem is ‘box tree blight’ for which there is no known cure or prevention. The blight initially presents as dark or light brown spots or lesions on leaves. The leaves typically turn brown or straw colour, then fall off. The stems develop dark brown or black lesions. The disease is fatal to young plants.
As bonsai they are effective but not easily trained. They grow easily from cuttings and produce a mass of branches needing very selective trimming. The branches are brittle and difficult to wire being frequently prone to branch die back for no obvious reason.
