Recent studies have documented numerous benefits of using bark as mulch. These mulches' activity against phytopathogens and their ability to control weeds and preserve soil fertility have been reported by several authors (Chalker-Scott, 2007), but the potential for the spread of disease has also been acknowledged (Prodoruttiet al., 2009). In this study, it was proved that A. gallica-infected bark used as mulch can infect a susceptible plant species, implying that Armillaria-infected bark used as mulch can represent adangerous source of inoculum in cropping systems.