Calling all green thumbs! If you’re looking for a way to get out in nature and give back to the community, help us tackle one of the most invasive species in our District- garlic mustard! The DeKalb Park District is asking volunteers to help eradicate the invasive species of garlic mustard (Alliaria petiolata). Invasive species are no joke. Garlic mustard is abundant and threatens native plant life in our area.