My 18month, 18 inch high Hansen Late Mandarin has almost nil growth this spring and is putting all it's energy into masses of flowers along the almost bare stems. The only leaves are old hard leaves.
I have been feeding it with a general citrus blend plus magnesium sulphate, PH is just slightly acidic.
Other citrus nearby are healthy.

This tree has me stumped..I hope it gets into leaf after this heavy blooming.
An ideas?

Pretty common. Some of my trees will do the same and once the bloom is done they will have a major flush of growth.