Brown Spots on Banana Leaves

Credit: TonnyBagget/iStock photos


Q: I have two beautiful banana plants, both are doing well. However, one of them keeps getting little brown sections on its leaves. I think they are from the water droplets I have occasionally seen on the leaves. Not sure. The other plant does not seem to have them. Could you please tell me what if that is the case and how do I combat that?

Having spoken to the tropical plant experts with whom I work, it seems there are two main possibilities. If water droplets sit on the leaves of a banana in the sun, it’s possible that the sun will create a sort of burn hole in the leaf. On the other hand, the brown sections may be due to edema, which is a physiological condition caused by uneven watering. This is not due to a pathogen, but rather due to the plant’s cells taking in water faster than they can release it. This can cause the cells to burst, sometimes releasing water droplets onto the surface. There are also a number of diseases that affect banana leaves. The most common in commercial banana groves is called black Sigatoka. It is cause by a fungus; you can see good photos and read a description at this excellent Iowa State University website

I recommend that you observe your plant closely to determine which of these seems like the most likely answer. You can wipe the leaves if they are wet in the sun and adjust the watering to see if that helps.