I'm not 100% certain on this, but I believe the Iron Phos targets primarily the slugs and snails by acting mainly as a repellent. The Spinocade, Spinocide, or however they want to spell it, targets other more leggy types by acting as a contact poison. I live in a state owned nature preserve that's highly organic at the surface. You can smell it--all the action going on with decomposition. The soil is teaming with all sorts of creatures. Slugs attack the tender noses of lilies here as well as baby stem bulblets. Cutworms are always a problem because they'll bite the stems off young offsets underground. This product will kill anything catapiller-like as well. As I understand it, Spinocade is a natural toxin produced by/derived from bacteria in the soil. I haven't observed any detrimental effects in the two years I've been using it.
