My house was basically built on a rock. I hired a contractor to enclose the crawl space under the house using pressure treated wood. He framed it all in and then used pressure treated wood boards to enclose it. He also added vents which can be open and closed. Insulation was then blown in and around the interior walls.

The outside is still wood and I am looking for a treatment that will match the house. Is it possible to parge the outside of the wood wall?

Don't think it would work too well. Expansion rates are much different. Adhesion on the bare wood is difficult.

If u tar paper and wire mesh the wood u would be able to stucco it. But as ma0641 stated the woods will expand and contract at different rates and may cause cracking over a period.

Chuck