Some of the leaves are curling. The tree is only 2 years old. All new lemons are either falling off the tree or turning dark brown. I fertilize every 6 weeks w/citrus fertilizer.
Lemon Tree Care/Potted
Certified GKH Gardening Expert
You may not be watering it enough. Potted trees need to be watered more than those in the ground. You need to make sure that the water gets all the way through the soil. If the soil is very dry, it may actually start to repel water. So enough water for another plant would not be enough to rehydrate this one. Give the soil a good, deep soaking at least once a week (in addition to regular watering) and that should ensure that it gets enough water.