I need to know how to trim lemon trees.
Certified GKH Gardening Expert
You can prune it in spring or summer. Lemon trees are pruned mostly to maintain a pleasing shape, so you can prune as you see fit to shape it the way you like. Do not cut off more than 1/3 of the plant per year as this can hurt the plant.
Lemon and lime trees are quite similar, including their care. Pruning lemon trees isn't any different than pruning limes. The following article should be of some help: https://www.gardeningknowhow.com/edible/fruits/lime/tips-for-pruning-lime-tree.htm