The plumbago plant (Plumbago auriculata), also known as the Cape plumbago or sky flower, is actually a shrub and in its natural surroundings can grow 6 to 10 feet tall with a spread of 8 to 10 feet. It is native to South Africa and knowing this provides the first clue to how to grow a plumbago, along with where to grow one. Plumbago thrives in the South African heat and in the United States it is found growing year-round in the southernmost parts of Texas and Florida.
It will grow as an evergreen shrub and makes an excellent foundation plant. It is beautiful when planted over a stone or wood retaining wall, allowing its branches to cascade over in a waterfall of foliage and unusual blue flowers—and it will bloom all year long. Because of its pest and disease resistance, how to care for a plumbago is pretty basic. It blooms best in full sun but will tolerate some shade if you are willing to sacrifice some of the bloom. As with most plants, it prefers fertile, well-drained soil, but again, it isn’t fussy. Slightly acidic, slightly alkaline, clay, sand or loam — where to grow a plumbago in your zone is really a matter of where to dig the hole!