Can I give my child up for adoption without the mothers consent?

My son is almost 8 months old. I have had him with me since he was 2 months old. DCF and Jewish Community Services placed the child with me after the mother decided to live with her mother in a different part of the state. When my son was born he had drugs in his system and that is how the authorities got involved. The mother was put on a case plan in November 2010 and it was to be completed within 6 months, when we went back to court. She didn't complete anything she was suppose to and continued to fail drug test. When i went back to court in April, she didn't show up and the judge gave me full custody. The mother only calls maybe once a month sometimes even longer. She has never given me any kind of support for him either. I'm just wondering since I have full custody of him if I could give him up for adoption without the mothers consent for any reason, or does she still have her rights and can prevent me from going through with the adoption?