Ask Burton: This week, we’re talking the lawn again – and how to head off a problem before it becomes serious. Q: I have a St. Augustine lawn and I’m starting to see irregular brown spots in it; the runners are still mostly green, but the leaves of the grass are rotting off right at the base, against the runner. This happens almost every fall, and I’d like this problem to go away. What is this, and how do I stop it?