When growing Calathea Zebrina, consider their natural habitat. Native to the understory of tropical rainforests in South America, Calathea Zebrina requires high levels of humidity, and they dislike bright direct sunlight. Brown leaf edges are a sign of low humidity or too much light. Fertilizer is important for Calathea Zebrina. We recommend diluting a general houseplant fertilizer by about half and applying monthly throughout the spring and summer.