I like all the suggestions posted here. Sounds like anyone of them will work (especially the pepper mixture). All my Golden pups dig when they are small but usually grow out of it by the time they are 1 year old. I spray bitter apple on the hole once they start digging. I don't cover it over until I'm sure they don't go back to it. They also get a stern NO when caught in the action.

Give your pup time and he won't dig anymore. Then you will be finding something else they do that you need help with. This is a good site get help from.