Can I whitewash directly onto stone?

Hello ,

I renovated a stone wall cottage and have sorted out most of the usual issues of insulation etc. I am left with a pebble dash on the outside but I can live with that, except on one wall. This side of the cottage was built into a bank of earth. They basically stripped off the topsoil, dug out the floor level and then just built on the subsoil. The result is the wall at that side of the house started two feet above floor level.

We have now excavated outside to below the floor and built up the stone from the floor up inside and the ground up outside. That's fine, but now I'm left with a wall that was part dashed and part bare stone. I have stripped off the dash to the base coat which I think is lime based. Can I just whitewash this wall or do I have to render over the stone first? Will the white wash act as a weather barrier? It's a very sheltered wall since we built the extension.

I have no knowledge of whitewashing so any advice would be welcome.

Thanks.