Digging to prepare a garden or grounds asks you to do the groundwork on yourself to move forward with regard to the subject matter of the dream. If the work is nearly complete in your dream it means that you have already done the groundwork and are now ready to proceed. That is a very positive indication.
Digging for buried treasure indicates you need to discover your spiritual abilities.
Digging your heels in shows that you are stubborn with regard to the subject matter of the dream.