6/15/2011 5:06 PM
Did you get your sprigs from somewhere in South Georgia? If so, the rocks are naturally occurring and came in with the sprigs. We see them everytime we sprig a new green with TifDwarf from farms in South Georgia, specifically near Adel, Georgia. They get picked up with the sprigs and delivered to you.
We sprigged a putting green two weeks ago and saw the same thing. I will try to post a picture for you tomorrow.