The prefered way would put as little wood in contact with the ground as
possible.
Consider fiber cement panels with pressure treated wood frame on top
and on two sides.
The side frames should be held 6 inches off the ground.
The ground in your photo looks dry, so you might get away with very
limited vents.
I would strongly recommend a vent on each side for cross venting.
You might investigate attaching the panels in a way that allows venting
around the panel edges.

TB