Botrytis is recognisable as a grey mould on the stems and foliage. This is one of the two main types of disease problems you are most likely to encounter when cultivating fuchsias. Botrytis can be prevented and even sometimes cured by allowing your plants a good circulation of fresh air. Another cure is to spray them with a systemic fungicide (available at the majority of Nurseries or Garden Centres).
Plants that are being over wintered will also require good ventilation. This is achieved by opening the windows and doors of the greenhouse during the winter when the weather is reasonably mild and dry.
This disease is recognizable by the presence of reddish brown ring markings on the upper leaf surface. The underside of the leaf will have what looks like orangey brown spores which are not dissimilar to rust in appearance. The first action to hopefully cure this menacing disease is the removal of any contaminated leaves and then immediately burning them. The plants are also thoroughly sprayed with an appropriate chemical that is available at any competent Nursery or Garden Centre. Isolate the infected plants and carefully inspect all the others to ensure that rust has not spread to any of them because this disease is very contagious and can cause major problems.
To prevent unsightly markings appearing on the petals, do not spray the plants with insecticide, fungicide or even clear water once they are in bloom.
Unfortunately we don’t live in a perfect world, and because of this we are aware that fuchsias, like many other adorable and popular plants, do occasionally attract such things as pests and diseases. At least with modern day fungicides and pesticides it is possible to keep both of these undesirables under manageable control. When administered to affected fuchsia plants as per the manufacturer’s instructions, they will eradicate the majority of pests and diseases you are ever likely to encounter.
Although not classified as a disease, some varieties of fuchsias produce dull reddish foliage when subjected to uneven temperatures or draughts.