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Garlic mustard is one of the few non-native herbs capable of invading and dominating forest understory communities. Its tolerance of low light levels, coupled with its high seed production and ability to spread rapidly, make garlic mustard a strong competitor. It diverts resources from native spring woodland plants. Because it begins growing very early in the spring, garlic mustard has a head start on other flowering plants and tree seedlings. Native woodland flowers are in danger of being crowded out by garlic mustard. It readily invades forested habitats where it can displace native plants, compete with timber species regeneration, alter soil composition and structure, impact natural associations between plants and fungi, and result in cascading ecosystem impacts.