Pelargonium zonale (L.) L'Hér.
Common names: horse-shoe pelargonium (Eng.); wildemalva (Afr.)
The flowers of this strikingly beautiful species range from pure white to rose-pink and all shades of red. Combined with its decorative rounded foliage, long flowering period, and ease of cultivation, it is one of the most rewarding shrubs for the garden.
Pelargonium zonale is an erect or scrambling shrub. It can reach a height of 3m but normally grows to about 1m. The young stems are hairy and succulent but become woody with age. The large leaves are often smooth, often with a characteristic dark horseshoe-shaped mark — hence its common name. The distinctly irregular flowers are borne in an umbel. Flowering occurs throughout the year but especially from September to November.
Distribution and habitat
Pelargonium zonale is widely distributed in southern Africa, often a conspicuous feature. It occurs from Piketberg in the Western Cape to the Eastern Cape, and as far north as the Underberg in KwaZulu-Natal, particularly common in the coastal areas of the southern Cape. It grows naturally in valleys and kloofs, on the margin of indigenous forest, and also on rocky outcrops with scrub vegetation.
Derivation of name and historical aspects
The genus name Pelargonium alludes to the shape of the fruit which resembles that of a stork's beak, and is derived from the Greek pelargos = a stork's beak. The species epithet zonale refers to the horseshoe marking on the leaves, zona meaning a band or belt in Latin.
The genus belongs to the family Geraniaceae, which includes four other genera: Geranium, Erodium, Monsonia and Sarcocaulon. There are ± 220 species within the genus Pelargonium, 80% of them confined to southern Africa and about 80% of these confined to the south-western corner of the country.
Zonal pelargoniums and hybrids are often commonly called geraniums or pot geraniums. This misnomer causes a lot of confusion. What is actually a Pelargonium is also known as a geranium, and what is actually a Geranium is also commonly called geranium or crane's bill. The two genera are easily told apart and are not mistaken for each other, but a gardener going to a nursery, asking for a geranium, but wanting a pelargonium is going to be surprised when shown a Geranium multisectum plant when expecting to see Pelargonium zonale.
Pelargonium zonale is a parent of many of the zonal pelargonium hybrids cultivated all over the world and is an integral part of any pelargonium breeding programme.
Growing Pelargonium zonale
Pelargonium zonale is an easy plant to grow, and does best in gardens where frost is not too severe. It requires semi-shade to full sun conditions. The plants should be pruned after flowering, and they respond very well to feeding with liquid organic fertilizers. They look very effective when used as the back-planting of a bed to form the main structure of the design. This species also grows well in containers.
Pelargonium zonale is usually propagated by means of tip or stem cuttings, or seed. The optimum time for taking cuttings is in autumn (March-May) and spring (September-November). Cuttings should be cut below a node and dipped into a suitable rooting hormone. The cuttings should then be placed in trays filled with coarse river sand. The medium should be pre-treated with a fungicide as a preventative measure against fungal attack. These cuttings should then be placed into cold frames for rooting. Seed can be sown in spring, summer or autumn.
Kirstenbosch National Botanical Garden
Plant Type: Scrambler, Shrub
SA Distribution: Eastern Cape, KwaZulu-Natal, Western Cape
Soil type: Sandy, Clay, Loam
Flowering season: Sporadic/All year
Flower colour: Red, White, Pink
Aspect: Morning Sun (Semi Shade), Afternoon Sun (Semi Shade)
Gardening skill: Easy