We can't get gr to grow on my father's grave, does anyone think Patch Perfect will work?

The only other thing we have not tried is sod. The grave site gets plenty of sun, but can't get any gr to grow. The caretakers claim that they have tried everything and if we have any ideas we can gladly use it. Please help. He's been gone for three years now, but his site looks as if he was just burried.