Question
Tom, When I moved in to my house many years ago, there was a circular drive in front that was mostly oyster shell composite.  Over the years I have tried to kill the grass coming up and finally gave up and let the grass take over.  Now, I want to reestablish the circle and put a     fine gravel down.  
First, I need to kill the grass and
vegetation.....permanently.  What do I use, do?  I would like to get back to the shell base and cover over that since it is almost rock hard as it was in the beginning.

I welcome your help and answers.

Thank you,

Mike

Answer
Mike:

Good question.  As far as I know, there is no permanent solution to weeds in a gravel driveway.  Maintenance is the answer.

You must be on the Gulf or Atlantic coast to have a shell base.  In that case, weeds will grow more months than in any other US location.  I would use a general herbicide, Roundup (or equal) and/or 2-4D first.  Then, I would apply a pre-emergent to keep seedlings down before the season in which each type of weed germinates, spring and summer.  In your case, that may be several times a year.  Finally, after the first treatment and pre-emergent, I would maintain the drive with Roundup or equal to suppress vegitation.

Drives in the mid-Atlantic region require such treatment three to four times a year to keep them weed free.

Paving is a long term solution, but still not permanent.  Asphalt decays and allows weeds to grow in cracks.  Concrete may be your best surface.  Stone will require replenishment every two to three years.

Best wishes.