The word "ferny" is quite specific in its meaning as it refers to a place or environment that is richly covered in ferns. However, there are several synonyms that can be used to convey a similar meaning. One such word is "foliage", which refers to all the plants in a particular area, including ferns. Another synonym is "verdant", which implies lush vegetation or a green landscape. "Sylvan" is also a suitable alternative, meaning a place that is related to or characteristic of forests. Finally, "leafy" can be used to describe an area covered in a variety of foliage, including ferns.