Please help! I have a banana plant in a container that I have had for several years. I place it outside in spring and in the sunroom in winter. For several months I have noticed that it has dark spots where the leaves meet the stalk. Is this normal? Now, the leaves are beginning to have large dead areas. I have removed these leaves to save the plant. Was this a good idea? The plant did produce a new leaf, but it has damage too. Should I cut off the remainder of the leaf from the stalk after it dies back or is this contributing to the problem? All remaining leaves have dead areas around their periphery.