Prune off damaged foliage after the threat of winter freezes has passed, because the dead foliage will help to protect the remainder of the plant from future hard freezes.
Spread a 3- to 4-inch layer of mulch on the soil surrounding your bird of paradise to protect the root system from hard freezes such as the one that damaged the foliage. These plants often return from the roots in spring if you keep the soil warm.
Cut all damaged foliage back to the base of the plant in early spring, when no more hard freezes are forecast. Using sharp garden clippers or a larger cutting tool, such as loppers or a saw, cut cleanly close to the soil surface.
Saw off all of the leaves to within 4 to 6 inches of the ground if a hard freeze has damaged a large percentage of the foliage. Be sure to wait until the threat of hard freezes has passed.