Amendment of soils with fresh and post-extraction lavender (Lavandula angustifolia) and lavandin (Lavandula × intermedia) reduce inoculum of Verticillium dahliae and inhibit wilt in strawberry

► Lavandula spp. reduce Verticillium dahliae by more than 99% in microcosms. ► V. dahliae reduction is only slightly diminished post-extraction of essential oils. ► Synthetic mixtures were nearly as effective as lavender and Brassica materials. ► Waste lavandin was twice as effective as waste lavender in microplots. ► In field plots results were mixed at three sites. ► Non-target effects were not found in functional and genetic diversities.