Is there a way to propagate Banana Lilies?
 

How do Banana Lilies propagate?

I've got a couple and even though they are cheap to buy, mine are going
berserk growing surface leaves all over and it would be nice to multiply
them before they take over the tank surface ;).

Would just cutting the surface leaves off and leaving them to float cause
roots or is the magic in the bananas at the crown?

Thanks for any info.

Oz