Aranon

So I planted a few Musa Basjoo plants in the yard last year and they grew fairly well over the summer. When winter hit it killed the leaves so I cut the plants back and covered them with a planter pot, and a trash bag full of leaves, then built a metal cage around them and put even more leaves in. Should have been the perfect protection but to this day they have not come back, the pstem I left above ground rotted as I expected but nothing came up from the corm. I am fairly disappointed. I keep going outside hoping to see some new growth even if it is too late in the summer but still nothing..

Any idea as to what happened? Granted last summer they weren't 10 feet tall plants but they had plenty of pups. I'm in Nebraska so we get cold winters but they had good protection from the cold.