I made a blog about my last year's winter protection of the musa basjoo, but they have grown larger this year so this year I am trying to protect up to 3 feet of the psuedo-stem so that they have a head start onto next year.
First I have the corm itself wrapped up in bubble wrap with wall o water plastic at the bottom for extra protection and that is topped with a couple of trash bags to ensure that the psuedo-stem stays as dry as possible over winter.
I am using left over fencing which is 40 inches high for the outside covering.
After stapling a circle of fencing to the ground, I fill it up very tightly with dried leaves which will serve as more insulation.
Once they are filled up, a few large leaf bags are put over the whole set up in order to hold in heat and keep moisture out.
Since heat can be lost from the top, I added filled leaf bags on top and attached them to the setup making them around 20 inches taller and increasing the insulation.
For less hardy bananas, I will just bring them indoors by a south facing window whenever it gets too cold, and expose them to as much light as possible over the winter to keep the psuedo-stem from elongating and weakening.
I collect hundreds of leaf bags for all purposes. On some of the smaller bamboos, I often use leaf bags to weigh down a tarp that I use for some of my bamboos, and use heavier objects like bricks or heavy branches if that is not enough to hold a tarp to hold the bamboo culms down to the ground over the winter.
As far as garlic, I add a layer of leaf much on all my beds of approximately 2000 cloves up to about 2 inches. I add it for insulation, to prevent them from heaving up, and hold in heat to aid in root formation as well as turning them into bulbs. This bed only has a little so far and will get mulched more before it starts to snow.