Sooty Mould

Garden Problems

Sooty mould is a fungal disease often associated with sap sucking insects. It grows on the sweet honeydew that scale, aphids and others produce.

Identify the problem
Sooty mould is found affecting many plants. It is often an indicator that the tree or plant is being attacked by sap sucking insect pests such as scale or aphids. The sap sucking insects produce the honeydew as a waste products and the mould grows on the sticky sweet substance.
How to solve the problem
- Control of sooty mould usually means the application of a fungicide to kill the mould and systemic insecticide to control the sap sucking insects underneath.
- Kiwicare PLANThealth Spectrum is a combination fungicide and insecticide that work well to control moulds and sap sucking insects.
- Use PLANThealth Spectrum or Organic Super Sulphur.
Did you know?
- Sooty mould is very common in the native beech forests of New Zealand. It is caused by a scale insect that sucks the sap of the beech trees and the bark of trees will often be completely covered in sooty mould. On close inspection tiny filaments can be seem emerging from the mould with a drop of honeydew at the end. The filament is the 'waste' pipe of the scale insect.
- Wasps are a problem in such forests because they feed on this honeydew. The vast amounts of honeydew can provide high energy food for vast numbers of wasps.
- Sooty moulds are caused by Ascomycete fungi which grow on sap from plants and the honeydew secreted by insects such as aphids, scale insects, the whitefly, and other insects which suck sap from their host plants.