Plumbago is an evergreen shrub with whip-like semiwoody stems that form a loose, rounded mound 3-10 ft (0.9-3 m)high with a similar spread. Plumbago can be pruned to grow like a vine and scramble over supports, or pruned into a more compact mounded shrub, or left to sprawl with its long, gracefully arching branches. The 2 in (5 cm) oblong leaves are a fresh, light yellowish green color. The sky blue flowers are 1 in (2.5 cm) long tubes expanding into 5 petals spreading about 1 in across. The flowers are borne in rounded terminal clusters 6 in (15 cm) across and look quite a bit like phlox flowers. Plumbago blooms all year long except for the coldest winter months. A white flowered variety (P. auriculata var. alba) is available. The cultivar, 'Royal Cape' has intense cobalt blue flowers.
Plumbago auriculata is native to South Africa, and is a popular ornamental in subtropical gardens in Florida, California and similar warm-winter climates across the world.
Plumbago add an elegant touch as it drips from planters at Miami Beach's fabulous Lincoln Road Mall (I think that's the fabulous gelato store in the background!).
Plumbago does best in light, sandy soils with good drainage. Do not add lime to the soil; plumbago likes a slightly acidic pH. The foliage may turn yellow due to manganese deficiency, but applying manganese sulfate will cure that. Plumbago should be pruned heavily to keep it neat and within bounds and to make it bushy to maximize the number of flowers. It produces its flowers on the current season's growth, so you can prune plumbago in late winter and not worry about cutting off flower buds.
Light: Full sun. Flowering will be reduced in partial shade.
Moisture: Plumbago survives with little watering once established, and is considered moderately drought tolerant.
Hardiness: USDA Zones 8B-11. Plumbago can withstand some frosts. Even if killed to the ground, it usually recovers quickly.
Propagation: Propagate plumbago from semiripe tip cuttings in summer. It can also be grown from seeds.
Plumbago is a tough beauty making it a perfect candidate for urban plantings as seen here along the sidewalk in front of the Miami Beach Botanical Garden.
Use plumbago in borders, foundation plantings, and for color massed in beds. Many gardeners use plumbago as a background or filler plant under and in front of shrubs that have stronger frameworks. Plumbago can be pruned as a formal hedge, or used in mixed informal hedges. Its rambling habit makes plumbago highly suitable for use as a flowering groundwave. Plumbago also is used as a porch or patio container plant that spills over the sides and showers the air with pretty blue flowers.
P. auriculata var. alba
Plumbago flowers bloom most of the spring, summer and fall in various shades of blue (buy plants in bloom to get the shade that you want). A favorite of butterflies, plumbago also is one of the most popular flowering shrubs in Central and South Florida gardens. It is very fast-growing, has few problems and is almost always smiling.