I would think that it would add strength if it is larger than sand no?
Is the DG like a small gravel in size or is it even smaller? I would love to find some fine DG as small as sand.
Where are you buying yours?
GB

Have never tried decomposed granite (though it sounds interesting) but I can tell you that "sharp" sand makes for a considerably stronger concrete mix. In fact, masons try and avoid sand that is too smooth or rounded because they know it acts like ball bearings under stress and fails earlier.

The DG I use is called Gold Fines and is very much like sand. I actually sifted it before and only got a few very small pepples. So the texture is like sand, but frankly I can't tell the difference between play sand and fine sand. The landscape material retailers sell kiln-dried sand of various grades. They tell me that is sharp sand - but it is more expensive.

The color of the DG I use is a lovely adobe color, maybe a little more golden than adobe. When used with white cement it looks like the hills of Northern California in the summer or the native stone around here. Which is the effect I am going for with my troughs. I just want to make sure they are strong enough.

We just bought a house in West Sacramento, CA and the back yard is covered with a fine gray decomposed granite.I am wondering if I can plant shrubs etc in this or do I have to amend it beforehand?