I got a lemon tree 3 months ago, and moved it to a bigger pot (outdoors) and applied fertilizer. Within a month, it lost all the leaves (while still green). Since then, many new leaves appeared (lighter in color and has no spots) and drop within couple of weeks. I noticed leaves with few spots as shown in the photo. I live in a very hot area where the temperature now reaches 45°C. I moved the plant into a relatively shady place where it gets about 3 hours of sun. Does anyone have a solution to this problem? Thank you.