Tribal cultures and religions around the world use specific herbs to invoke positive influences, send prayers and cast out negative energy. One common ceremony is to burn certain herbs, this is called smudging or censing (incensing). In North America the three plants most frequently used in smudging are sage, cedar, and sweetgrass. The smoke from these herbs is used to clear any unwanted energy before or during a ceremony, within a home, or surrounding an object or person. The smoke is used to facilitate prayers, encourage healing, and bestow blessings and honor.