For many years the common wisdom for gluing down scenery texture was to spread your material, sawdust, groundfoam or what ever, soak it with "wet" water and then dribble in thinned white glue.
Whenever I worked that way this would result;
A not very interesting cross between moonscape and Passchendaele. And not the desired result.
So a little thinking and experimenting followed and I've come up with this approach.
I start with filling in the open spaces with extruded polystyrene, I used to use a cardboard lattice and plaster bandages, took too long.
That can be shaped, sanded, carved to one's hearts content.
Over top of that I apply a thin layer of Sculptamold. I really like this product. It has a reasonable working time and when dry has just the right amount of texture. It can be troweled while wet and it sticks well to the foam.
Over that comes the first layer of texture and colour.
I brush a coat of thinned white glue first and thin sift "Burnt Grass" over the entire area. Sort of a primer coat if you will.
Once that dries, another coat of glue is brushed over the surface.
All that for another day.