, fungus gnats
and Botrytis cenerea
are very common pests and diseases that can affect many plants, and they are probably some of the most stubborn too. Each one can cause considerable damage to your plant and it is not always easy to get rid of them.
This CANNA Pests and Diseases Guide provides some background information about these common pests and diseases (including the biological cycle), and tells you all you need to know about symptoms, prevention and control.