Peace Lilies

I never anticipated peace lilies growing outwards more than upwards! We recently had to shift the plants around the living room--the palm mysteriously died, and we got an old stereo system and speakers by the TV...so we tried to put the peace lily where the Chinese Evergreen was...but it wouldn't fit! It has sprawled horizontally a good couple of feet in each direction. Even the miniature one on my desk is spreading...