Boxwood (Buxus sempervirens) is a slow-growing evergreen shrub with small glossy leaves, used for low hedges, edging and topiary. It tolerates sun and partial shade and most well-drained soils, preferably slightly alkaline (pH 6.5–7.5), but dislikes waterlogging and heavy clay. Plant container plants from spring to autumn, about 15–20 cm apart for a low hedge, and water regularly in the first season. Trim twice a year, in late May or June and again in August, on an overcast day so the cut leaves do not scorch. Two problems have made box harder to grow: the box tree moth, whose green-and-black caterpillars can strip a hedge within weeks from May onwards (check inside the plants and treat with Bacillus thuringiensis), and box blight (Cylindrocladium), which causes brown leaf spots and bare patches in wet weather. Keep plants airy and water at the base. Japanese holly (Ilex crenata) is an alternative where problems persist.