Late summer flowering
Hardy, easy to grow and beautiful, this family is a shady solution
FEBRUARY is normally the hottest month in Durban, and we have been fortunate to have lots of rain. I took a walk down the Krantzkloof Nature Reserve this past weekend, and the river that runs through the reserve was the fullest I have seen it in months.
Late summer brings into flower many of the colourful trees, shrubs and groundcovers plus a number of bulbs which creates such beauty, especially in the upper Highway region. One tree in particular is the African tulip tree, Spathodea campanulata, with its orange tulip-type flowers that stand up above the foliage.
The Kloof Project, which is a group of volunteers who landscape and maintain all the gardens in the precinct, planted 120 trees in the past year. These trees, after all the rain and heat of summer, are starting to show signs of growth and maturity. If each one of us planted one tree or shrub, we would have millions of trees to enjoy.
I have been in touch with like-minded groups in Durban North and Westville following our example and that of the Keep Hillcrest Beautiful Association which maintains the gardens of our suburbs.
February is one of my favourite times of the year because we have a particular group of plants that flower in late summer and which bring so much colour to our gardens.
Plectranthus, better known as the spur flower, belongs to the mint family (Lamiaceae), and is the largest South African Genus in this family, with 44 species growing mostly in the eastern region of our country. Plectranthus gets its name from the Greek word plektron meaning spur and anthos which refers to the base of the flower tube.
South African species have some of the showiest garden plants, providing a mass display of colour in late summer and autumn. Colour selections vary from purple, pink to white and many shades in-between. Typical of the mint family, the leaves, when crushed or brushed against, are very aromatic.
Plectranthus is easily cultivated and requires little attention once established. Because of its shallow root system, some species will require lots of water. Some of the more hardy species store water in their thick stems and can survive dry periods. They enjoy a wellcomposted soil, and as a rule do well in a semi-shaded, cool position on a south-facing aspect. If you have a shady area under a tree this is where they do best. Other than their attractive flowers, some species are grown for their foliage such as Plectranthus zuluensis. Growth forms vary from dense prostrate ground covers to large shrubs.
Plectranthus is frost-tender but survives because most species grow in shady places like forests. Because most species flower at the end of the growing season, frost does not affect the flowering. If damaged by frost, cut back at the end of winter and allow new growth to push through in the summer growth period. Once established, they become hardier to frost and drought. Most shrubby species must be cut back at the end of winter one-third to a quarter of their height before new growth begins for summer.
In Durban, you can cut these plants back just after flowering because we don’t have the same cold dormancy period as in the frost regions. After pruning, add a thick layer of compost or organic mulch and an application of fertiliser such as 2:3:2 around the base of the plant. Ground cover species require little pruning except to clean up old growth and flower spikes.
Most ground cover species have attractive foliage that forms dense attractive carpets that vary in height from 150mm to 450mm producing an abundance of flowers in autumn.
They are ideal plants to grow in rockeries and Loffelstein walls as they root easily from the nodes whenever they touch the ground. Shrubby species can grow to 2m and should be planted en masse. I have Plectranthus ecklonii growing in full sun and doing well but on the whole it prefers a shady spot.
Plectranthus is easily propagated from cuttings which should be done in early spring or summer.
Here is a list of the most commonly grown Plectranthus in Durban, available at most nurseries: Shrubs:
Plectranthus ecklonii – large shrub which grows to more than 2m in pink, purple and white. Probably the most common one grown in domestic gardens. Easy to grow in sun and shade. Plectranthus zuluensis – soft hairy dark green foliage with dark blue flowers. Must be grown in deep shade and does require water or it wilts badly. Probably one of the most beautiful of all the species. Plectranthus ambiquus – grows up to 1.2m in height with purple flowers that branch from the base. Grows in deep shade. Plectranthus fruticosus – grows up to 2m with pale to deep mauve flowers. Grows in deep shade. Plectranthus saccatus – grows up to 1.2m with mauve to blue to white flowers. Does well in a container or semi shade. Ground covers: Plectranthus ciliatus – grows up to 600mm in semi shade. Requires moisture to flourish. Flowers from September to May. An outstanding ground cover or container plant for damp shaded areas. Grows easily from tip cuttings.
known as the money plant, is one of the hardiest of the ground covers and does best in rockeries, Loffelstein walls and hanging baskets. Easily grown from tip cuttings and has flowers that vary from white to pale mauve with dark spots. Plectranthus neochilus, the lobster flower, is the hardiest of all the Plectranthus ground covers. Grows well in full sun and shade. Flowers in terminals that are greenish white and edged purple. Best grown in retaining walls and on steep banks.
This article is sponsored by Chris Dalzell Landscapes, specialising in landscaping, consultation and botanical expeditions: email address: cgmdalzell@gmail.com or visit www. chrisdalzellinternational.com