Ceratostigma – Popular Shrubs for the Garden
Ceratostigma willmottianum, the species usually grown, is a hardy Plumbago. Its rich blue, produced in clusters, much resemble those of the true Plumbago, that is often seen in conservatories and which has flowers that are a paler blue.
This shrub is perfectly hardy and can be grown in the open garden, where it makes a plant about 18 inches tall, its flowers beginning to appear soon after midsummer and continuing until September or October. The growths are usually cut by frost in the open garden, but no permanent damage results and it is only necessary to give the plant a trim over in April to remove the frost-killed shoots and new growth will soon start to appear. This in fact is the only form ofrequired.
Against a sunny, sheltered wall Ceratostigma willmottianum may reach 3 feet in height and is less liable to frost damage. Another good place to grow it is in the herbaceous border, for its blue flowers associate well with the yellows and reds of the later summer border plants.
The foliage is a bonus because in the autumn it turns yellow and red, adding to the colourfulness of this useful shrub. It will grow in any kind of, including those containing much chalk. Plants may be lifted and divided for propagation purposes in much the same way as herbaceous perennials.
See: More Popular Shrubs