bonsaial1

I think the granite issue can be summed up by, where did the decomposed granite come from. I know when I had my pool built, I had a waterfall built into the pool. 15 tons in the fall, and 20 tons on the bond beam. Looked real cool, but I digress, I had about 10 tons of boulders in my front yard and thought I could save some money by useing the stones I allready had. The landscaper sent a guy out that had a rock testing unit. They chisled off a portion of one stone, and put it into a crushing unit. The stones failed. The stones were not dense enough to be used as structural units. What does this have to do with granite in your soil mix, plenty. I feel that decomposed granite is in all states of decomposistion. We have a granite pit here in Sanger that has provided D.G. for about 50 years. It is very hard holds up well under motor traffic in driveways, but I would not use it in my potting mix. Why, well it is still undergoing decomp. The stuff is brittle enough that if used in soil mix it will breck down as Rip says and clog soil. But,,, if you use the granite that the southern Cal. guys do, I'm speaking of folks like John Naka, Harry Hirao, Ernie Kuo, Roy Nagatoshi, Richard Ota, Mel Ikeda, etc., you would see a differance in the granite. The D.G. from the Mojave desert is very old. You could say that the D.G. from this area is done decomposing. It is the consistancy of safety glass that has been shattered. Sort of little polyhedrons of quartz. there are no minerals left. This stuff is very inert. Once it has been sifted for size, I don't think it would breakdown in our lifetimes. The grey stuff that we have here in the valley is very young on the oldness scale and is still very actively decomposing, you can sometimes smash it in your bare hands. I think the bottom line is, Try it one season, I don't think the D.G. would be the reason you might lose a tree. You might find out that it is great, or just the oposite. I don't like uniforms in school and I think everyone should try things and see what works for them. It would be a boring world if we had cookie cutter soil.

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