Jenn Martinson wrote:... Borage is sounding like the best bet...
D Nikolls wrote: ... that's a much better description of what I meant by using a rock.. they could be better than concrete in the right place with the right rock.. cheap, local, low carbon, and potentially more durable.
Gotchas that I can see are:
A) Not as resistant to frost heave vs a concrete pillar with a mushroomed base below the frost depth..
B) Only as durable as the rock you pick; some are excellent and some suck..
If you are drilling a hole in said rock for the post anchor, you might use that same hole for a lifting eye.. a lever and come-along attached to a vehicle can lift a surprisingly big rock..