I have a Fiddle leaf fig that has recently developed large brown spots on the leaves. I have the plant for over 6 months and it has done GREAT until now. I only water it when the soil on top is dry and the tree get ample sunlight. Any ideas??
Brown leaf spots on Ficus lyratas are a generic symptom with no one cause. Improper watering is the most common cause, but inadequate light and using hard water may also cause these spots.
Let’s start with light. I don’t know what you mean by “ample light,” but I do know that most folks tend to overestimate light intensity. Your Lyrata should be right in front of a sunny window that is completely uncovered throughout the daylight hours. If it is more than a few feet from the window or off to the side, it is probably not getting enough light. The symptoms of inadequate light develop slowly over several months or more.
You may not be watering enough. Assuming your tree is in its original nursery pot, then it should be watered as soon as the surface of the soil feels just barely damp. Apply enough water so that a small amount trickles through the drain holes. If your local tap water is hard, use filtered or distilled water.
The existing leaf spots will never go away. Your goal should be to prevent new spots. However, a certain amount of leaf spotting is inevitable because conditions in the home are always less than perfect.