A bump feed trimmer head is designed to release more cutting line without the operator having to stop the motor. The head is equipped with a spring-loaded bump knob in the center. When the line becomes frayed or worn down, the user simply taps the bump knob on a hard surface like the ground while the head is spinning. The centrifugal force from the spinning head then causes a short, measured length of new line to be released from a spool inside the head.