Mandarin leaves are curly by nature. I was worried but when I went to an orchard I saw that it was same story there.

Thanks for the feedback. I'll post my pictures, but I don't see any sign of insect damage. Perhaps this is as you say, a species-specific idiosyncrasy! Cheers, -Eric

My Clementine, Caffin, Gold Nugget, Tango, S.Kishu, leaves curl, cup, go up, go down - when dry, wet, cold and hot. Its what they do.

All systems normal; - Eric your tree looks good!

Roger that and thanks! It hasn't fruited yet, but it is only a 2-3 years old, so I guess that will come in time. I haven't pruned it particularly, but have been trying to get it to grow into a bamboo trellis. It has been cooler here in San Jose, so perhaps the curl is a response to that. Cheers -Eric