The line trimmer has become almost as common as the lawn mower for landscapers and gardeners. It gives lawns that finished touch with all the edges neatly trimmed. Young trees with thin bark are particularly sensitive to damage from line trimmers. Trimmers make little nicks and cuts in the bark which can gradually cut all the way through. The inner bark contains the tubes which transport food made by the leaves to the roots. If these tubes are damaged, root growth is reduced and top growth becomes stunted. Completely cutting bark all the way around will kill a tree. Maintaining a circle of mulched soil around young trees will not only protect trees from trimmer damage, but reduce competition for water and nutrients, resulting in faster growth.