Dwarf Musa Banana - stunted growth and dying leaves

[Fahmy]

Hi,

I have a dwarf Musa Banana which is around 3 years old, I have been keeping it indoors in front of a south window and it has been growing vigorously for the past years, since mid august I noticed that the plant is not growing any new leaves and suddenly it starting losing leaves quickly, the leaves would go yellow and then black in a matter of days, and from 20 leaves it went down to 3-4 leaves with this rate there will be no leaves left in two weeks !

I gently removed the dead leaves and the stem lost like 80% of its size

The plant has a couple of pups growing and they look healthy, soil is a good draining soil with 10% perlite and 10% expanded shale
I used to fertilize with a banana fertilizer every other week during spring/summer

any advice to save the plant is highly appreciated, pictures below,

Thanks,

 

[cpp gardener]

The soil looks great. Have you ever leached it? The way to do that is to put outside or in the bathtub and water it until there is water on top of the soil. Let it drain until it stops dripping and then do that 2 more times. This will remove leftover fertilizer salts in the soil.