An appropriate course of action would be to arrange a conference with your son's teacher and the guidance counselor at his school. His teacher is probably aware of the problem. Together, you can develop strategies to help him deal with these problems. For example, he can be taught to put together a calendar of all his assignments so that he can track work when it is due. As he completes tasks, he can be rewarded with the opportunity to participate in another activity that he enjoys. Two books that provide helpful information on these topics for gifted children, their parents, and their teachers are School Power: Study Skills Strategies for Succeeding in School by Jeanne Shay Schumm and Sylvia Rimm's book How to Parent So Children Will Learn.
Gifted, Slow, and Disorganized
Gifted and Talented Expert Advice from Rita Culross, Ph.D.