Hello michelle, Im not familiar with your climate so its a bit hard for me to help. can you give any more information on whats happening? what is your climate doing at the moment? how much are you watering?

Ill try to put your link in here because it was a bit hard to find

Here is a link that might be useful:

It looks to me like a Pelargonium peltatum cultivar - the Ivy Leaved Pelargonium. The necrotic area could just be caused by a drop of some kind of chemical used near where the plant is situated. It could even be sun scorch through a drop of water.
Overwinter - keep just moist and in good light at a minimum temperature of 5C until spring when cuttings may be taken and eventually planted out or grown in a pot or hanging basket.

Here is a link that might be useful: website

Hi Michelle,
Is this plant in a container indoors or outdoors? Peter is correct to suggest scorching but if the container is outdoors it could be slug damage. I would recomend that if the plant is the ground you put it in a plant pot and trim off all, or as much as possible, of the affected foliage and overwinter as he suggested.
Bon chance
Ron

Sorry for not replying sooner, I was called away unexpectedly and was delighted to read all your helpful answers upon returning. We have hot and dry weather in the summer (around 112°), now we are down into the 90Âs, no sun, no rain either. My geranium is in a hanging basket in the shaded part of the terrace (21 feet above ground level), I never use chemicals apart from a nicotine based spray I make from friendÂs cigarette buts to kill greenfly. No slugs but some big crickets and the odd scorpion. I have not watered it in 5 days, the leaves are turning yellow and the flowers are gone. Peter, I think you are right. A neighbor watered my plants for me during the holidays and he moved it from the shade to full sun, he must have watered it during daylight hours (2 other plants have similar "holes" : the surphinia and the sweet peppers  all in containers on the terrace). On the other hand I have just noticed some severe traces of chewing on other plants (and one of the eggplant veg. has been almost totally eaten away). Can bats or swifts do this? IÂll overwinter as you say, do you think it will flower again and should I put some fertilizer in the soil? Many thanks again for your helpful answers