Plectranthus zuluensis

Plectranthus zuluensis with Justicia carnea

This is an excellent South African Plectranthus, known colloquially as the Zulu spurflower, which grows into a loose shrub about 2 m in height. It has bold, striking plumes of soft blue flowers that appear in flushes through most of the year, with a brief respite in winter and early spring. The flowers resemble those of Plectranthus ecklonii, which blooms in later summer and autumn, It has attractive scalloped-edged foliage. It will flourish in sun or shade of any sort, and copes well with dryness. Mine grows with a free-flowering, dwarf pink Justicia carnea nearby; it also looks beautiful meandering through Hydrangea shrubs, as it is in bloom when they flower. It also looks lovely with another South African shrub with rounded blooms of the same hue: Thunbergia natalensis, which likes to grow in semi-shade. In its native environment, it grows in forests and along forest margins. I have also seen it look lovely next to a tall specimen of the lime green-flowered Nicotiana langsdorffii. In South Africa, there are some named cultivars, including some with deep purplish-blue flowers, which sound alluring.

Prune the plant back in mid to late winter once flowering ceases, and apply some general fertiliser at the same time. It can also benefit from occasional light trims to keep it from getting too big! Every few years, replace the plant with a cutting; these strike easily if taken in spring or autumn. It also self-seeds a bit, and these can be used as replacements. They are easy to pull up if there are too many of them!