I'm in dire need of some suggestions for rescuing my backyard. I've got three retired racing greyhounds who have destroyed the existing St. Augustine. The area is largely shaded (less than 50% sun during the day), long and narrow. The dogs live indoors, and probably spend less than 5 minutes a day outside. That said, they can hit 45 MPH in just a few strides and do enjoy a good game of doggy grab ***. Suggestions?