My lemon tree has dropped its leaves due to over watering in the pot. When can I replant my tree into the ground?
You didn't say where you live. Where you plant the tree has a profound effect on the survival of your tree. If you live in areas known for growing citrus (The Mediterranean Region, Brazil, South Africa, Peru, Guyana, Suriname, French Guiana, Southeast Asia, Southeast India, Madagascar, Southern Japan, Northeast Mexico, Northwest Mexico, Eastern Australia, Florida, and California) you can plant your lemon tree any time that you want.
Check here on GardeningKnowHow for growing lemon trees: