If you need a shrub for those difficult sunny areas in your garden, the attractive yellow flowering Justicia odora is just the plant that you are looking for.
Justicia odora is a shrub or perennial herb up to 1.2 m. The leaves are ovate and glabrous (no hairs present) except for a few hairs on the midrib and margins. The leave stalks are short. The stems and older branches have a whitish colour. The flowers, in small clusters in the axils of the leaves, are bright yellow, veined at times, with a red or purple inside tube. Justicia odora is a medium fast perennial and will reach maturity in a year's time. It flowers from September to May.
Distribution and Habitat
The natural distributions of the plants is in the warmer parts of Kwazulu-Natal, Mpumalanga, Namibia, Botswana and also widespread in tropical Africa. It grows in full sun on hills in stony soils. It tolerates light frost and is able to withstand very dry conditions.
Derivation of name and historical aspects
The genus Justicia was named after James Justice, a Scottish horticulturist. The species name odora means fragrant. It belongs to the family Acanthaceae. In the genus you get perennials, suffrutices (most of the plant grows underground), shrubs, rarely small trees and very rarely climbers. The fruit is an explosive capsule, and the seed often have water absorbent hairs. Other species in the genus are the yellow flowered Justicia flava and the mauve flowered Justicia capensis.
Insects pollinate Justicia odora. It is especially attractive to various species of butterflies.
Uses and cultural aspects
The roots are fragrant and in some parts of the world they use the roots for perfumery, drinks and herbal tobacco, or the roots are rolled into perfumed 'beads' which remain fragrant for a long time.
Growing Justicia odora
Propagation by cuttings is the easiest why of growing the plants. Cuttings are taken during October, November and December; by using plant growth of the previous season. The cuttings should be 120 mm and treated with a growing hormone like Seridex No1. hormone powder. Plant the cuttings in a mixture of good soil, compost and river sand in equal parts. The ideal temperature for rooting is between 15-28°C. Water twice a week. Transplant the rooted cuttings in a good soil mixture and place it in 60% shade. There are no known pests that attack Justicia odora.
Justicia odora needs full sun and will do well in the rocky parts of the garden.
Plant it together with other succulent plants to get the feeling of a bushveld garden.
References and further reading
- Poole, E.1998. Wild Flowers of Kwazulu-Natal and the Eastern Region.
- Baden, C. Balkwill, K. Getliffe Norris, F.M. Immelman, K.L. Manning, J.C. Munday, J.1995. Flora of Southern Africa, Volume 30.
Lowveld National Botanical Garden