Had a winding path of the above material installed. Brick soldier course on either side of the slates with some space between slates.

Basically, I'm pleased with it. However, I was under the impression that some sort of stone dust would be used and when wetted down would harden.

It appears the material is a gravelly beige sand which is soft, and I know this will be a problem with rain and feet, etc. I can gauge my gait to step on just the slates, but sometimes there are little ones here.

Is there anything I can mix in with the sand to harden it? The thought of it being a litter box is horrible.

I've already had thoughts of moss, thyme etc to fill in, but will they grow in the sand?