Final answer:
To fix brown spots on a fiddle leaf fig, identify the cause such as under-watering, over-watering, root rot, or fungal infection, and correct your watering schedule, improve drainage, remove affected parts, or use a fungicide if necessary.
Step-by-step explanation:
To fix brown spots on your fiddle leaf fig, you need to identify the cause of the browning first. The most common causes are under-watering, over-watering, root rot, or fungal infection. If the spots are on the lower leaves, it might be due to under-watering. In this case, ensure a consistent watering schedule that allows the soil to dry out slightly between waterings.
If the top leaves are affected or if the spots have a yellow halo, it's likely over-watering, so you'll need to let the soil dry out more between waterings and ensure the pot has proper drainage. For root rot, you may need to repot the plant into fresh soil with adequate drainage and possibly trim any blackened roots. In the case of a fungal infection, remove affected leaves and consider using a fungicide. Regularly cleaning the leaves and providing adequate light and humidity will also promote the health of your fiddle leaf fig.