Plectranthus zuluensis
Plectranthus zuluensis
Durban - It is hard to believe that just over two years ago we were on water restrictions because of the crippling drought in KwaZulu-Natal.
This past month we have had more than our fair share of rain. It has caused some damage, but also brought lots of relief to farmers and gardeners. 
It makes gardening more affordable when we don’t have to water our gardens, but it also makes us so aware that it just takes a few months of no rain for problems to arise. Please don’t waste water.
With all this rain, I have been watching one particular plant flourish this month. It grows in deep shade, has soft, dark velvet leaves and produces beautiful blue flowers in November. Plectranthus zuluensis, better known by its common name, Zulu spurflower, belongs to the Lamiaceae or mint family, which are usually highly aromatic because of the presence of essential oils, and include such well-known culinary herbs as lavender, rosemary and thyme.
There are about 300 known species in the genus Plectranthus, of which about 48 occur in South Africa, mostly in the eastern regions. The name Plectranthus is derived from the Greek plektron, meaning spur, and anthos, meaning flower. This particular species gets its specific name zuluensis because of its distribution in Zululand.
Today it is grown by most nurseries throughout South Africa and found in most gardens, particularly in KZN. With its delicate blue flowers and velvety leaves, Plectranthus zuluensis is a winner for difficult shady areas in summer rainfall gardens.
Plectranthus zuluensis is an erect, sprawling, soft shrub up to 2m high, with branched, four-angled, hairy stems which are velvety to the touch when young. 
Its soft, semi-succulent leaves are ovate with coarsely toothed margins and covered with tiny, colourless glands. When crushed, the leaves give off a characteristic pungent smell. 
Flower spikes which appear at the ends of the branchlets, are 60 to 100mm long and bear the flowers in whorls of six with colours ranging from deep purple-blue to pale blue-mauve. 
The main flowering time is from October to June, with a peak in April. 
It is found throughout the coastal regions of the Eastern Cape and KZN, all summer rainfall regions with little or no frost. 
It likes a rich humus soil and is popular because it grows in shady areas. 
It is best grown with a number of other shade-loving plants such as Clivias, Streptocarpus, Crinums and Scadoxus. It can be pruned once a year to keep it in shape, but it needs water or this delicate plant will wilt and look very sad. They can be grown in containers on your deck or patio, but must be in the shade.
It is easily propagated by doing soft tip cuttings in spring or early summer. 
Make sure you select a healthy plant and take the cutting from the growing point. It is best to use a sharp propagation knife and take the cuttings just below the nodes. 
You can either remove most of the leaves or cut the leaves in half to reduce water loss. 
Place the cuttings in a seedling tray using a well-drained medium such as river sand. Keep moist in a well-ventilated shady position and water daily. 
Roots will develop in 3 to 4 weeks, when the cuttings can be moved directly into your garden. Water well during those early days because the plant will experience some stress. 
It is best to grow Plectranthus zuluensis in a well-drained humus-rich soil in a semi-shady position in your garden. You can fertilise throughout the summer season with 2.3.2 every few months. 
Once the plants have finished flowering you can prune to remove dead and diseased wood. 
It is susceptible to a number of scale insects, white fly and aphids but generally the essential oils in the leaves keep these plants insect resistant. 
Eelworm can be a problem so treat the soil with a nematacide as eelworms attacks the roots of the plants. Watch out for rust, which is a fungal disease which attacks the plant when under stress. On the whole this is a very rewarding plant that will do well in all gardens in the greater Durban region. 
It is important to try to plant your garden with different plants that flower throughout the year. 
For example, in the next few weeks the pineapple plant, Eucomis autumnalis, will flower, giving a new dimension to your garden. These grow best in a semi-shady position and will flower from now until the end of January depending on where you live. 
I always love hiking in the Drakensberg in late December as these plants flower in the grasslands. It is a fun plant to find because it hides in the long grass and is difficult to find unless you are looking for it.
The Independent on Saturday