 <unk> , items able to ward off revenants , are common in vampire folklore . Garlic is a common example , a branch of wild rose and hawthorn plant are said to harm vampires , and in Europe , sprinkling mustard seeds on the roof of a house was said to keep them away . Other <unk> include sacred items , for example a crucifix , rosary , or holy water . Vampires are said to be unable to walk on consecrated ground , such as that of churches or temples , or cross running water . 
