Go to Scenic Express and take a look at what the carry for grasses. What I use the most are Silfor tufts, a very natural looking product which lookslikes wild grasses, not a golf course. They also make strips of grass which would work great in teh middle of youtr dirt road.
I add texture to my Celluclat by mixing railroad ballast in with the Celluclay. I also add cheap brown acrylic craft paint into the mix along with Elmer's type gule.
Dirt and sand, unless ground exceeding fine, will look out of scale in 1/35. Better to rough up the surface and paint.
Since discovery the stuff at Scenic Express and Military Miniatures Warehouse I rarely use traditional Woodland Scenics static grass or turf products. No disrespect to them, but the newer products are miles ahead, especially in larger scales.