Potty training advice

My 1-year-old Shih Tzu Toby who just turned one in August, just started going outside instead of a potty pad. However he will walk outside for almost 30 minutes pee on every tree. Then he comes in and gets his treat for being a good boy. And 5 minutes later he will go to the potty pad and poop. Do you have any tips or tricks to get your dog to poop outside.

My 1-year-old Shih Tzu Toby who just turned one in August, just started going outside instead of a potty pad. However he will walk outside for almost 30 minutes pee on every tree. Then he comes in and gets his treat for being a good boy. And 5 minutes later he will go to the potty pad and poop. Do you have any tips or tricks to get your dog to poop outside.