Costus glaucus is named for the whitish "glaucus" covering on the new shoots, bracts (usually) and other vegetative parts, but it is not the only Costus that ever has that appearance. It is closest to Costus laevis and I have sometimes gotten them confused in the wild. What distinguishes C. glaucus besides the glaucus is the longer lobed ligules, over 15 mm and up to 55 mm. It is also usually much taller, up to 20 feet tall and with straighter stems.
It has large leaves and a colorful flower against the green bracts. I have usually found it growing in sunny areas and it should do well in full to part sun. I have not tested this for hardiness and assume it would only be hardy in frost free areas.