Rosemary was known to ancient practitioners. It was an herb known for strengthening the memory and helping the brain and was often cultivated in kitchen gardens. Roman priests used rosemary as incense in religious ceremonies, and many cultures considered it a herb to use as protection from evil spirits and witches. In England, it was burned in the homes of those who had died from illness and placed on coffins before the grave was filled with dirt. For magical use, burn rosemary to rid a home of negative energy, or as an incense while you meditate. Hang bundles on your front door to keep harmful people, like burglars, from entering. Source: learnreligions.com