A: John recently wrote in and provided this picture. He says when he bought the lemon tree last year, it had a lot of blooms on it. His theory is that the store had applied a lot of fertilizer to promote blooms so it’d sell. He may be right.
In my opinion, the slow onset of new leaves reflects a need for nitrogen. If his above theory is correct, the nursery would have used a fertilizer higher in potassium to promote all those blooms.
I think thinning the citrus is a good idea, just the same as for apple, peach, and plum trees. I know it hurts to remove some of the fruit, but much needed energy is then sent back to the plant for even better fruit that remains!
Leaf growth could be slow because of a lack of nitrogen. A good time to apply a citrus-branded fertilizer is when the tree is initially brought outside in the spring, after the last frost has passed, then again in September.