ZEP, I have tried all of it at my farm in East Texas! The absolute best is crushed concrete. No dust, does not migrate down in to the soil, tightens up in wet weather because the fines wash down into the voids and then loosen up in dry weather. Guaranteed to be 99.9% free of metal. Will be pricy but is the best next to paving.
Tom Sterling (Shelby County).
