You are going to have to reward with treats and lure him into the lawn over time... Keep it 100% positive back there. Like reeljake said it could have been ants or a loud noise or something that scared him while in the yard. If he acts scared don't try to comfort or pet him, or you end up basically rewarding that behavior and making it worse by encouraging it. It's better to have him sit and just hang out with you and give him treats until he realizes on his own that there's nothing to be afraid of back there... my 2¢

We have dog who doesn't like to get her feet wet, so won't go on the grass when it's dew-y in the morning, or just sprinkled. DH doesn't like to walk barefoot on grass either. Are you hoping to get your puppy to do its business on the grass instead of the rock garden? A rock garden seems like an easy place to pick it up....

Some dogs just don't like grass or some other surfaces. I know that with a clicker and treats, it is certainly very do-able to get the dog onto the grass, and attach a command to it, but to persuade the dog to choose the grass for playing, seems really challenging. Maybe play fetch with a toy or tennis ball on the grass.

I would get the puppy into some training with a trainer who can teach positive rewards training (for you), so you can learn ways to motivate your dog to choose desirable behaviors. It's hard to know if this is just a temporary puppy "fear" or if the puppy has formed some kind of opinion that between grass and other surfaces, he prefers other surfaces.

Have you considered that maybe the dog knows something you don't? Just sayin' :o)

My boyfriend actually today read on another forum that maybe the dog is very smart and wondering why your luring him out there, and keep giving him treats and he's just curious and he can tell that we're trying so hard, so he's scared that there's something he doesn't know that we do, today we came home and I just walked outside by myself and ignored him and he came right out and sat and layed on the grass and played fetch (which he hasn't done in two months) and actually didn't even want to come inside, I let him make his own decision to come on the lawn. it's crazy to think about how much your dog pays attention to your behavior and what it means to him! So wish me luck and hope that this continues

That's fantastic!! Great insight. Training is easier when we put ourselves in the dog's position, and try to understand their motivation. And you rewarded the behavior with a lot of affection and playtime. You are both great puppy-parents! :)

Maybe my joke wasn't so far off after all. Cesar Millan says most of his time is spent training the owners, not the dog.

Yeah I mean we spent so much time trying to make him do something and he was scared that we were trying to do that? I mean I still don't know how it started but we were reacting the wrong way

My wife and I have five dogs, all are rescues and all have totally different personalities. Our latest is a female American Pit Bull Terrier. She is so in tune with people she can sense your emotions and state of mind and reacts accordingly. All it takes is the slightest uncertainty on my part and she will shut down so I have to be extremely conscious of my mental state. It's amazing at how much I have actually learned from her.

Yes!! That's awesome our dog is a rescue too and clearly must have the same state of mind as her! Learning every day!!

Get rid of all the ultrasonic crap and all the oils you are putting down. Half of that stuff is probably contributing to the dogs reluctance. Let the dog have a stable environment and it will learn to love it. Don't leave the dog alone in the yard, either --- your presence will help calm the dog. Just keep yourself calm and act like being in the backyard is. I big deal.