Ceratostigma (Hardy plumbago)
Common name: Hardy plumbago
The Ceratostigma genus comprises deciduous dwarf shrubs that flower from mid-summer to early autumn. The bright bluenestle among the sharply pointed deep green summer leaves, which take on tints of red and copper in autumn.
There are three species widely available. First there is Ceratostigma griffithii, a native of the Eastern Himalayas, with small blue flowers. The most widely known is
Ceratostigma willmottianum (AGM), which originates from China and flowers in late summer It can often be cut to the ground during the winter by sharp frosts, but new growth usually appears in the spring.
Ceratostigma plumbaginoides (AGM) also comes from China. This is a neat plant that can be grown on the rock garden, used as ground cover, or allowed to trail over a wall. It produces terminal clusters of blue flowers from mid-summer until the first frosts. The foliage takes on autumnal tints.
Soil type Most humus-rich, well-drained soils are suitable.
Planting Choose an open, sunny spot, but one that is not subjected to cold winds.
Maintenance No regularis necessary. In late winter any old straggly shoots should be cut back to ground level.
Propagation Take cuttings with a heel from sun-ripened shoots, during mid-summer
Pests and diseases Generally trouble free.