Red-hot pokers are grown in temperate gardens around the world. Ranging in colour from reds, oranges through yellow to lime green and cream, numerous cultivars and hybrids have been developed from species originating in South Africa.

The genus Kniphofia was named in honour of Johannes Hieronymus Kniphof, 1704-1763, who was a professor of medicine at Erfurt University in Germany. Kniphofia belongs to the family Asphodelaceae which comprises 17 genera (10 of which occur in South Africa) and about 750 species. About 70 species of Kniphofia occur in Africa and 47 of these are found in the eastern areas of South Africa.The genus Kniphofia is very closely related to the genus Aloe. As a result, the first Kniphofia to be described, namely K. uvaria, was mistakenly thought to be an Aloe and was thus initially named Aloe uvaria.

Most species of Kniphofia are evergreen while a few are deciduous and sprout again in the early summer. They bear dense, erect spikes (elongated inflorescence with stalkless flowers) above the level of the leaves in either winter or summer depending on the species.The small, tubular flowers are produced in shades of red, orange, yellow and cream.

Kniphofia form large clumps of arching leaves which are long, narrow and tapering. The leaves are non-succulent, unlike the leaves of aloes. This distinguishes them from a plant such as Aloe cooperi. The leaf surface is glabrous (smooth) in all but one species, namely, K. hirsuta.

The underground part of the plant consists of a thick rhizome and fibrous, fleshy roots. In some Kniphofia species the rhizome divides forming groups of stems, while in others the stems are more or less solitary. The vast majority of Kniphofia species do not produce an aerial stem, but exceptions do occur as is the case with old specimens of K. caulescens and K. northiae which can reach a height of 30 cm.

Kniphofia are frequented by nectar-feeding birds such as sunbirds and sugarbirds. They are also visited by certain insects. The flowers of some species of Kniphofia are reportedly used as a minor food and apparently taste like honey. K. parviflora is reported to have been made into a traditional snake repellent. K. rooperii and K. laxiflora are used traditionally as a medicine. An infusion of the roots is used to relieve or treat the symptoms of certain chest disorders.

Kniphofia spp. occur naturally in all the nine provinces of South Africa. Kwazulu-Natal possesses the highest number of Kniphofia species, compared to the other provinces with ± 40 to 50 species. Kniphofia also occurs in Lesotho, Swaziland and northward towards Sudan. The species diversity, however, decreases as one moves north. Three species occur naturally outside continental Africa. Two of these species occur in Madagascar and one in Yemen. Most Kniphofia species are found growing near rivers or in places where conditions will become damp or marshy for part of the year. A small number of species prefer dry conditions with good drainage.

Growing Kniphofia species

Red-hot pokers make a brilliant display in a garden and the flowers last for a long time. The showy, bright-coloured flowers are ideal for adding a splash of colour to an area or making a bold statement. These plants can be used at the back of a mixed flower border, in groups in the front of a shrub border, or lining a long driveway. Kniphofia tolerate wind well and are often seen growing close to the coast. They also make excellent cut flowers. The winter-flowering varieties are particularly useful in providing displays of colour during the dry winter months in the summer rainfall regions.

Kniphofia grow well in rich soil located in an open sunny position or partial shade. Most species require plenty of water during the growing season if they are to thrive and flower well. They should also be fertilised monthly during their active growing period. Kniphofia species are generally hardy to semi-hardy. Most species tolerate frost but the winter-flowering species should be protected. Some summer-flowering species die down in winter and grow again in the early summer. In cultivation Kniphofia resent disturbance. They will take a year to settle down after being divided and will not flower well. They should therefore be left undisturbed for many years until their flowers show signs of deterioration through overcrowding. Some commonly cultivated Kniphofia species include K. praecox, K. linearifolia, K. uvaria, K. multiflora, K. caulescens and a variety of attractive cultivars.

These plants can be propagated by seed or by division. Division will produce the quickest results since seed takes a long time to produce flowering plants. Large clumps can be lifted and divided, using a spade and then replanted.

Acknowledgements: Mr Syd Ramdhani is thanked for providing information on the distribution of the genus.

References

• ELIOVSON, S. 1984. Wild flowers of southern Africa, edn 7. Pretoria.
• JOFFE, P. 1993. The gardener's guide to South African plants. Tafelberg Publishers, Cape Town.
• POOLEY, E. 1998. A field guide to wild flowers of Kwazulu-Natal and the eastern region. Natal Flora Publications Trust, Durban.
• TRENDLER, R. & HES, L. 1994. Attracting birds to your garden in southern Africa. Struik Publishers, Cape Town
• 
  VAN DER SPUY, U. 1971. Wild flowers of South Africa for the garden. Hugh Keartland Publishers, Johannesburg.

Marc Stern
Witwatersrand National Botanical Garden
July 2002