I have several shrubs where the leaves are getting covered in a black sooty matter. How can I remove it?
This is caused by plants suffering from an aphid,or scale,attack.The infested plants become sticky with honeydew excreted by this insect,and further disfigurement occurs when sooty mould grows on this substance. Often by the time you spot the mould the insects have moved on or retreated into the the plant’s stems for the winter months.The cure is to treat the plant with an insecticide, such as Provado, to stop the cause. On evergreen plants you can wipe the mould off,or on larger infections,water the plant over the foliage once every two weeks with a fine rose watering can.Add a few drops of washing up liquid to the water,this has the effect of helping rain water to penetrate the mould and start to wash it off the plant.This method works best on camellias and bay trees.
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