Hi ~ Having a designated potty location is a great idea and the one you have described sounds like it will be great once your dog understands this is where he has to eliminate.
Often times, dogs develop a *substrate* preference and making a transition to a new one (in your case, from grass to mulch covered gravel) confuses the dog. This often is the case when making a transition from paper to the outside. Your boy seems to prefer grass. So....give him grass! It may help if you take several pieces of sod from the garden store and place them in (and perhaps around) your new potty location for your boy. You may even want to place a piece or two where he usually relieves himself and then take *that* piece of sod and place it into the 5X7 potty area. Besure you reward him heavily for eliminating where you want him to. You will want to use a leash (not sure if you just let him out at this point) and walk him to the desired area. He will get the idea soon enough especially if he is rewarded generously and enthusiastically. Good luck ~ Helen Hollander, CPDT The Educated Pup, LLC Lawrence, NY APDT # 5888P x12//03 "Be mindful that happiness is not based on possessions, power, or prestige, but on relationships with people you love and respect. "