Despite the many health benefits of going outdoors, it's admittedly tough to find time to venture outside. Not only can houseplants add some natural flair to your home, but they can also help improve air quality, boost your mood, and possibly improve cognition. Peace lilies are perennials that are commonly planted indoors because of their dislike of direct sunlight. This preference for shady conditions also makes peace lilies among some of the easiest houseplants to grow. If placed outdoors for any period of time, note that the plants are considered hardy in zones 11 and 12.