If excavating in rocky soil, you might find it difficult to go as deep as 2'. You can make your work a bit easier by whittling the bottoms of your 4 forked poles to a sharp point. A pointed pole can easily be driven a few extra inches into the ground, since it offers less resistance.
For this optional whittling operation, there is no good substitute for a hatchet. However, it may be advisable to skip this optional step if you have no experience in wielding a hatchet. Hatchets can be dangerous if not used wisely. By the way, note that, although it's somewhat counter-intuitive, a sharpened hatchet is less dangerous than one with a blunt blade. The latter is more likely to careen wildly off the object being cut and strike your body. But by giving a hatchet-blade a sharp edge, you increase its chances of biting into the wood properly, which, in turn, increases your control over it.
With the excavation done, on Page 7 we turn to installing the vertical poles....
