Have you noticed plants in your garden with blackened leaves or stems? If so, it is highly likely that your plants are suffering from what it commonly known as SOOTY MOULD.
SOOTY MOULD is a secondary fungal infection that feeds on the sweet, sticky excrement of sap-sucking insects such as aphids and mealy-bug. This ‘Honeydew’ as it is commonly referred to, is exuded by the insects onto the plant creating a favourable environment for the growth of SOOTY MOULD. The mould coats the leaves and stems of plants eventually suffocating them by reducing their ability to absorb sunlight for photosynthesis and thereby causing the plant to age prematurely or die. So in the warmer climate when sap sucking bugs thrive, we often have problems caused by these insects. .
To eliminate SOOTY MOULD you must first eradicate the insect pests. You can do this quite easily in a number of ways. Use an oil-based insecticide that coats the plant hindering access to the sap or manually remove the pests by hand or hose. Also eliminate any colonies of ants near problem areas. Ants are friends of these insect pests and kill any natural predators they have. You can do this either with Ant-Kill products or by simply planting Tansy which is a natural repellent to ants. In turn the Tansy will then encourage natural predators to these insect pests such as lady-bugs, lacewings and parasitic wasps.