Granite Dust – Harmful?
Q: Recently I had a flagstone patio installed in my back yard. They used granite dust between the stones. A lot of it ended up in my empty planting beds. Will the stone dust harm any plants I put in? Will it change the pH of the soil?
A: Granite dust is not dust-like; it’s a coarse sand that works well in loose-laid paver installations. It has a pH close to neutral, so it won’t change the acidity of the soil. The good news is that it WILL help change the drainage in your beds for the better. My recipe for good planting soil includes 1 part coarse sand mixed with 1 part soil conditioner and 1 part clay. Too bad you didn’t get an extra load of the granite dust to use in your other beds!