[Overview]
A deciduous or evergreen shrub to small tree.
The leaves are usually simple and opposite, with pointed tips and short or soft hairs.
The flowers are tubular with a 4-lobed tip and are borne in spike-like or panicle inflorescences.
The fruit is a capsule.
[Cultivation]
Propagate by cuttings.
It prefers sunny, well-drained, fertile soil.
The roots are coarse, so it dislikes being transplanted.
For potted plants and plants in the ground for less than 2 years, water thoroughly when the soil dries; for established plants in the ground, rainfall is sufficient unless summer brings a long spell of sunny weather and the soil becomes severely dry.
Fertilizer is not particularly necessary.
The branches grow vigorously and the shape easily becomes untidy, and if the branches become too crowded, flowering is poor and aphids infest the plant, so in March prune the branches that grew the previous year, dead branches and crowded parts.
Flower buds form on the branches that grow in spring, so finish pruning before the branches start to elongate.
Pests and diseases include aphids and longhorn beetle larvae (teppo-mushi).
