A beautiful hardy pelargonium is suited for a miniature rockery.
Pelargonium ternatum is a well branched evergreen shrublet. It has an erect or procumbent growth habit, 0.2 to 0.6 m high. The stems of the plant are woody and slightly rough to the touch. They are green when juvenile but turn reddish-brown and finally greyish-brown on maturity. The leaves are three-foliate, slightly fleshy and leathery, some with long and some with short petioles. The flowers, white to pink, are mostly borne singly and always in the axil of a short-petioled leaf. All five petals are narrowly obovate, with the two posterior (upper) petals noticeably longer and wider than the anterior (lower) three. This species flowers during most months of the year except February and March, but has a peak period in September.
Pelargonium ternatum is listed on the Red List of South African plants (Raimondo et al. 2009) as Least Concern. A taxon is Least Concern when it has been evaluated against the five IUCN criteria and does not qualify for the categories Critically Endangered, Endangered, Vulnerable or Near Threatened.
Distribution and habitat
This pelargonium species has a rather limited distribution in the Langeberg range in the southern Western Cape. It is only known over a range of not more than 50 km, from the vicinity of Montagu in the west to near Riversdale in the east. It occurs mostly at altitudes of 300 to 600 m. Near the coast it forms a component of the vegetation type Coastal Renosterbos veld, dominated by Elytropappus rhinocerotis. In the mountains it occurs in False Macchia, which is considered to be an in-between vegetation type between Dohne Sourveld and true Fynbos. These vegetation types consist of dry, low, shrubby, sclerophyllous (hard-leaved) vegetation. P. ternatum grows in rocky terrain often in well drained sandy soil. The distribution area receives an annual rainfall of about 200 to 400 mm near the coast and as high as 600 mm in the mountains. The rainfall pattern is evenly distributed throughout the year. The summer months become quite hot, winters are mild, and light frost is experienced at elevated localities. According to Van der Walt & Vorster (1981) “After a veld fire in Garcia's Pass in the 1976 an extensive population of P. ternatum appeared on the burnt section, suggesting that the species acts as a pioneer in an early stage of plant succession.”
Derivation of name and historical aspects|
Pelargonium ternatum belongs in the Geraniaceae family, a large cosmopolitan family of approximately 11 genera and 800 species in subtropical and temperate regions of the world. There are approximately 270 species of Pelargonium which occur in S, E and NE Africa, Asia, St Helena, Tristan da Cunha, Madagascar, Australia and New Zealand, most of which (219 species) occur in southern Africa. The genus Pelargonium gets its name from the resemblance of the shape of the fruit to the beak of a stork, pelargos in Greek, while the specific name ternatum, in Latin, means 'in threes', and refers to the three leaflets or lobes of the leaves.
Pelargonium ternarum and Pelargonium fruticosum are fairly closely related, but nevertheless distinct species occurring in adjacent areas and separated by slightly diverse environmental conditions.
The seed is adapted to wind dispersal; it is light in weight and has a feathered, spiral, tail-like attachment. When the seed lands and there is sufficient water in the soil, the tail acts like a drill, twisting the seed into the soil so that the seed can anchor itself in the ground and is thus prevented from being blown away, or carried away on moving animals.
Uses and cultural aspects
There are no cultural aspects linked to Pelargonium ternatum but it is an excellent garden subject.
Growing Pelargonium ternatum
Pelargonium ternatum can be propagated from both seeds and cuttings. Stems 100 to 150 mm long can be taken at any time of the year from a healthy vigorous plant. Select softwood or herbaceous growth from the plant. The plant material selected should also be free of pests and diseases, and it is best to remove any flowers present on the stems as well. The use of a rooting hormone powder will speed up the rooting process, especially for the softwood cuttings. Place the cuttings in river sand in cold frames and keep them moist. If you do not have cold frames then a well lit warm area in the garden will do. The cuttings should root in 2-4 weeks. Give the rooted cuttings a 2–3 week weaning or hardening-off period and transplant them into a well-drained potting soil mix and place them in a sunny position. Feed with an organic-based liquid fertiliser. As soon as they have formed a strong root-ball they can be planted out into the garden.
Sow seeds in late summer to early autumn. The seed should be sown in a light, well-drained potting mix. Sow the seeds evenly in the seed tray and cover them with fine white sand or fine-milled pine bark. Water the seeds gently but thoroughly with a fine rose spray and place them in light shade with no direct sun. Seed germinates in 2–3 weeks.
This Pelargonium is able to adapt to most gardens like many other Pelargonium species as it experiences a range of environmental conditions in its natural habitat. It will thrive in cultivation and is well suited for your rock garden. In the Western Cape the best time to plant is during the rainy months of winter to allow plants to establish themselves before the warm, dry summers. It prefers a sunny spot in your garden. Pruning is usually done in late summer to early autumn. This provides the plant with enough time to grow again before winter sets in. Pelargoniums need to be cut back to keep them neat and vigorous. Remove any dead growth as well. This will provide you with a good flowering plant for many years to come. Happy gardening.
References and further reading
- Brown, N. & Duncan, G. 2006. Grow Fynbos plants. South African National Biodiversity Institute, Newlands.
- Goldblatt, P. & Manning, J.C. 2000. Cape plants. A conspectus of the Cape flora of South Africa. Strelitzia 9. National Botanical Institute, Pretoria & Missouri Botanical Garden Press, Missouri.
- Raimondo, D., Von Staden, L., Foden, W., Victor, J.E., Helme, N.A., Turner, R.C., Kamundi, D.A. & Manyama, P.A. (eds) 2009. Red List of South African plants. Strelitzia 25. South African National Biodiversity Institute, Pretoria.
- Van der Walt, J.J.A. et al. 1981. Pelargoniums of southern Africa, vol. 2. Juta, Cape Town.
Kirstenbosh Botanical Garden