I arrived home from work today and my mandarin has developed some black blemishes on the leaves. Some of the newer leaves are even falling off. I wonder if it is succumbing to the same issue as my kaffir lime, or if it didn’t take well to the foliar feed of iron chelates that I sprayed it with the other day. Should I do nothing, treat for root rot, or something else? I have no idea! Why can’t this be easier?
My gut feeling is that I have some issue related to overwatering. There have been some mushrooms growing around the base of my trees, so surely that means they have been too wet. I think I’ll make the call that it’s root rot, and flush the roots with a weak bleach solution. All I can do is kill it, right? 😦
500m2 in Sydney 
Probably the foliage feed (did you do on a hot day?) but could be also because you are inadvertently watering leaves? I have a geranium that keeps giving my curcubits powdery mildew. Plant stds … !
Tee Hee 🙂 Don’t think it was a hot day, but aren’t they all at the moment ?!