My dog is being possessive over a hole?!?

ok so i have a rose garden and my dog, sadie dug one of the rose bushes out and started digging there. well i am going to get the whole area redone so i just let her dig there for now but the thing is whenever my other dog goes near it sadie's hair goes up and she guards it. it got scary when my other dog went there and started digging and then sadie came back and started growling at her and showing her teeth and they almost got in a fight and they are two mediu-large ssized dogs and it would be dangerous if they got in a fight. Soooooo what im asking is how to make her stop being possessive over it or even stop digging there completely.