lwhile I agree that feeding it and keeping it in light will help, I disagree that it will likely drop more leaves. BE SURE you introduce it to outdoor sunlight slowly. Put it in morning sun for a couple hours a day for the first week or so, then gradually increase it by a couple hours a day. Otherwise you will learn about leaf scortch. That tree should be able to handle a good 10 hrs a day full sun during warm weather. In the fall when temps drop below 50F at night consistently, bring it in and just keep it alive. Give it as much light as you can (south facing window if possible) and feed it less than you did when outside. I have a ficus benjamina forest that is probably 15 years old and it never loses leaves. It's pretty much hard to hurt.