Olive trees aren't easy to grow in the UK and black spot fungus makes the task even harder. Black spots on olive trees is a sign that the trees are being weakened and damaged by black spot fungus. Immediate treatment with a fungicide is one of the most effective ways of eradicating the fungus and restoring infected olive trees to good health.
Fungal spray
Apply a fungal spray as a preventative measure or as a cure when you first notice the fungus. Preventative fungicides can be applied in the early spring, while curative fungicides should be used only when the black spot fungus appears.
Herbicide function
Preventative fungicides, in addition to care such as irrigating the soil around the olive trees, make it more difficult for fungal diseases to grow. Curative fungicides help to kill off existing fungus and spores and stop the damage.
Other treatments
Prune dead branches and remove affected leaves to help stop or slow the spread of black spot fungus between olive trees.