The intensely colored dwarf plumbago blossoms appear dark indigo in indirect light. Click to download a large version (800x600).
In sunlight the blossoms appear bright violet-purple and seem to fluoresce. In any light they are beautifully bluish! Click to download a large version (800x600).
Dwarf plumbago has pretty deep blue flowers that look a lot like those of true plumbago (Plumbago auriculata). In fact, the two species are members of the same botanical family, and were once included in the same genus. The Latinized suffix, -oides, means "like" or "similar to" - Thus Ceratostigma plumbaginoides is a Ceratostigma that is similar to plumbago.
Dwarf plumbago is a bushy mat forming perennial which spreads across the ground with wiry branching rhizomes, and sends up numerous slender, erect stems about 12-18 in (30-45 cm) high. The stems are reddish in color and the bases can be quite woody, but the upper parts are herbaceous. The deciduous leaves are about 3.5 in (9 cm) long, have wavy margins, and turn a rich orange-red in fall. Small clusters of brilliant sky blue flowers top upright stems in late summer through fall. The long lasting flowers have five petals and are about 3/4 in (2 cm) across.
Location Ceratostigma plumbaginoides is native to western China.
Culture Light: This attractive groundcover does well in full sun to partial shade, but in the warmest climates it should get shade during the middle of the day. Moisture: Dwarf plumbago likes a moderately moist but well drained soil. Hardiness: USDA Zones 5-9. Dwarf plumbago is the hardiest species in the genus. It can withstand temperatures as low as -4°F (-20°C). However, it will definitely benefit from a layer of mulch during zone 5 winters. Propagation: Young softwood cuttings can be rooted in spring. Divide off rooted suckers any time during growth.
Dwarf plumbago makes an beautiful ground cover that's in bloom over a long season in the summer and fall. It is fairly fast growing as demonstrated by this dinner plate sized clump that was started from a small sprig of root and stem three months earlier.
Dwarf plumbago makes an excellent (albeit deciduous) groundcover around shrubs, at the front of beds, or in a sunny rock garden. It is also used as a border, but must be kept in bounds. In northern climates it has been been used as a bedding annual, and in frost free climates it is sometimes used for erosion control on steep slopes. Dwarf plumbago drops its leaves following frost, but resprouts dependably in late spring, and then blooms on the current season's growth. Blooming is best on new, young growth, so in frost free areas, cut back the old flowering stems in late winter. Dwarf plumbago is a good choice to plant with spring bulbs since its foliage is just coming into its own about the time the crocuses, tulips and daffodils are giving up the ghost.
There are eight species of Ceratostigma. They are small shrubs or woody based herbaceous perennials, occurring in Southeast Asia, the Himalayas and one species in the Horn of Africa.
Under ideal growing conditions, dwarf plumbago might become a little bit invasive.