Care for a banana tree during the winter by trimming and covering the tree to protect it from colder weather. Banana trees require protection of their underground rhizomes during the winter. Protecting the pseudo stem allows the plant to recover faster when warm weather returns.
To winterize a banana tree, you need a clean and sharp machete, mulch, fleece blanket and a plastic garbage can. If the tree is planted in the ground, cut the plant down, and leave about 3 feet of the trunk before the first frost. Apply 4 to 6 inches of mulch to the root area, and wrap the trunk with a fleece blanket. Use the plastic garbage can to cover the banana stump from cold temperatures. Once winter has passed, remove the garbage can and trunk wrap from the tree.
For banana trees housed in a container, begin by slowly withholding water from the plant over a period of time to allow it to become dormant before winter. After the first light frost, trim the tree's main stalk, leaving it level with the pot. It's normal for foliage to begin turning a dark color after making the cut. Relocate the plant to a dark and cool spot between 40 and 45 degrees Fahrenheit. Watered throughout the winter just enough to keep the soil from pulling away from the container. After all signs of frost have passed, return the tree to the outdoors.