Groundcover Repels Garlic Mustard! Sturdy rootstocks and soft green leaves creep to cover woodland slopes, rocky soils, and any shady area. Once established, Wild Ginger (Asarum canadense) fends off Garlic Mustard, Buckthorn, and other invasives. Wild Ginger keeps its foliage throughout the season and does not go dormant, so it is a good species to plant among the spring ephemerals that do go dormant. Unpalatable to deer and other mammals, it is an important food source for the Pipevine Swallowtail Butterfly. Plant one foot apart to form a solid cover in two to three years. Hardy to Zones 3 - 8.