| Hi Jan, it looks like Bacterial leaf spot, seen most on ivy geraniums. Organic control: Remove and burn infected leaves prune affected branches 30-40cms below the damaged area. Chemical control: Spray with copper oxychloride ( 50% ) at the rate of 2.5g per litre of water. Jan you may be able to buy a prepared one now. This book I got the Info from was printed in 1994 so ask at a Nursery. Tip: Avoid overhead watering. Increased spacings between plants may lower humidity and reduce problems with this disease. No doubt the writer of this article did not live in Queensland. Hope this helps. Cheers...MM. | 
