Antimicrobial compositions based on a combination of plant essential oils of enhanced antimicrobial effectiveness are prepared by adding to the combination of at least two plant essential oils, a small but antimicrobial enhancing effective amount of an enhancer selected from the group consisting of polyionic organic enhancers and polyionic inorganic enhancers. One preferred composition it is a mixture of plant essential oils wherein at least one of the oils is oregano oil.
