We have two male Golden Retrievers that are about eighteen months old. They don't dig when we are around but only when they are at home by themselves.
A: ~ They are still young and bored. I have heard of lots of tricks, but none that are proven to work. Why aren't they inside?
~ There is getting a sandbox and burying bones and toys (gives them something to dig for and a place to only dig at) You can teach them that is good digging and the other is bad.
~ I have heard burying there poop where they dig, eventually they will learn they will only dig up their poop and will stop digging.

Comments: 2
every dog, like human kids, is different. but typically by 2 years.
Golden will totally stop growing at 2 years old. Then they start to fill out!
Hope this helps!