The mould/fungus can be peeled off the leaves,it also appears on the mulch surrounding these plants. Have sprayed with white oil could not see any mites/bugs. Could you please give me some advice? It started to appear after all the rain we had in January. The garden where the plants are planted do not get a lot of sun as they are shaded by a large tree & palms.
16 April 2012 05:07 AM
I think it is likely that the mould appearing on your plants is Sooty Mould. This fungus is black and dry and looks like soot. It can be easily wiped or washed off the leaf. It grows from the honeydew that is produced from sap sucking insects such as aphids and soft scales. Wherever the honeydew appears, the mould can grow. The mould does not directly harm the plant but it does inhibit photosynthesis which can affect the growth of the plant. You have taken the correct action by spraying the foliage of your plants with Yates White Oil. If there are insects present, the oil will suffocate and kill them. The oil will also help to loosen the mould which can be easily washed or hosed off.