Winter Hedgerow - stage 1

I am just painting this before going on to "Dawn of the Hamadryad" as the idea just popped up and felt duty bound to try it. It might not work out but it will be useful for "Dawn...." so hopefully I won't be wasting my time. I want this to be more of a pattern with one tone pretty much across the whole picture although I have included a fairly dynamic compositional use of the tree trunk etc so it should be lively...and subdued...at the same time...
Stage 1 is the tonal underpainting pushing around a paint mix of Burnt Sienna and Winsor Violet with a battered synthetic brush and then erasing with a small bristle brush dipped in clean turpentine.
I rarely throw a brush away, old knackered brushes are great for mark-making and textures.