Posted: 28/05/2015 at 12:20
Dont know where you are John but drying out and over watering would cause this. Did you simply take it outdoors from being inside without hardening off?
i grow several pelargoniums and yellow leaves occur anyway now and then. I just pick them off. Pelargoniums do not like dead or dying leaves around them. More because of neglect, my plants do dry out a little too much at times but a good watering resuscitates them...this does create a few yellow leaves too
i grow pelargoniums outside too...they generally do better outside in the summer.....with some kept there over winter.