Buried Treasure? Peruvian Seabird Guano is a natural fertilizer that contains nitrogen, potassium and phosphorus. Nitrogen derived from Seabird Guano can enhance growth and plant vigor. When blooming and ripening fruit, good phosphorous levels are very important. It can be used indoors or outdoors on vegetables, herbs, flowers, ornamentals in soil or can be used to make a tea for hydroponic applications. Buried Treasure? Guano is pelletized for easy use. Does not contain fillers.