The Boston fern (Nephrolepis exaltata), also known as the sword fern, is a popular fern species that grows in many tropical areas around the world. The Boston Fern is most commonly kept as a house plant, especially because it doesn’t have high sunlight needs. The foliage of this fern remains evergreen. Its sword-shaped, blue-green fronds with many tiny leaflets are erect and arch as they grow larger. Like several other fern species, the Boston fern is a fairly slow grower and is best planted in the fall or spring.