I apologize for this delayed reply to your gardening question and hope it is still helpful to you.
Bermuda is difficult to eradicate prior to the growing season. Once it warms up enough for the bermuda to start growing well spray the lawn with glyphosate (Roundup is one brand) and give it a week to 10 days to move down into the roots. Then you can rototill the area lightly, water, and wait another week or to to watch for resprouts to respray. When you are satisfied it is gone you can lay the new St. Augustine lawn.
Thanks for the question. Best wishes for a wonderful gardening year in 2007. Please stop in again soon!
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