Garden Line Equipment such as lawnmowers and string trimmers can clog up if the grass being cut is damp or wet. It is advised that grass is cut or strimmed whilst dry. This reduces clogging greatly. The string trimmer head / grass box flap serves its purpose more effectively if kept clean and free from old grass cuttings as this reduces build up, allowing the grass to move away from the string trimmer head / grass box flap. Always remember to unplug any electric power tools before performing any cleaning or maintenance.