There are numerous kinds of banana plants, and they all weather winter differently. Many types that are planted in the soil outdoors need to be insulated against the cold. If a banana plant is fairly hardy and experiences moderate winters, sometimes all you need to do is wrap the top with cloth after the leaves blacken from frost, and then mulch the roots. However, more finicky varieties or those in harsher weather may require you to cut back damaged foliage from the base of the leaf stalk after the first frost. Next, use four wooden pallets or something similar to build a small enclosure about 3 square feet (0.28 square meters). If the banana plant is taller than the structure, add another set of pallets. Loosely pack straw inside the box and cover with roofing felt to protect the plant from rain. For smaller, single-stemmed banana plants, you can place a chimney pot or drainpipe over it and pack with straw instead of building a structure. Take potted banana plants indoors.