The plants are only 1-2 years old, are all potted plants. Some leaves have a mottled appearance as per photo. On occasion, back of some leaves look like they have been invaded but can't see any pest
08 October 2011 10:08 PM
Geraniums are very prone to rust which is seen on the underside of the leaves as brown pustules. Caterpillars such as green loopers also enjoy eating the leaves. I suggest you try a product like Yates Rose Shield which contains both a systemic fungicide and insectide. Water under the leaves and this will also help reduce the incidence of disease.