I have a dwarf lemon tree that is dropping it’s leaves.
I have had this tree only since last Christmas and it was healthy. I potted it with a good mix and fed it regularly, I only water it when nearly dry. It has dropped most of its leaves and looks very sick. I live in an area that has very heavy frosts and it was out in the elements before realising that maybe it was being burnt. Can I prune it? It was a gift from my grand daughter and therefore very precious. I’m not sure which variety it is but I think that lemonade was part of its name? Regards Lyn Johnston
Yours is probaly a "lemonade lemon tree", a hybrid between lemon and mandarin orange.
You need to protect it from the frost. It can take the full sun but not temperatures below freezing.
And water it before it dries out completely, it may be drought stressed from water deficit as well as frozen.
From the photo it does not appear dead. You can save it with better care.
Yes you can prune off the driest, possibly dead branches, but don't prune off any live green growth now, it needs that for recovery.