Certified GKH Gardening Expert
Unless you live in a warm climate, it is best to grow peace lily indoors or in a container outdoors for easy overwintering inside. They cannot tolerate cold at all. In addition, outdoors they require bright light but not sunlight, as this will quickly scorch the plant, which may be what has happened with yours. You can cut away the spent bloom and make sure it is located in a suitable area. Partial shade is best. Also, ensure that the soil is kept evenly moist but not soggy.