The first banana plants I purchased was back in fall of 2009, 2 musa basjoos which survived until I tried to bring them indoors and over-winter however the lighting was not adequate enough and those ended up rotting.
I then bought a couple more in spring of 2010, small 2 inch pt musa basjoos, and these grew to 4-5feet in the season even after being planted 1 foot deeper than soil level. Here's the result of last fall.