Diatomaceous Earth, or DE, is far more effective than any other pesticide because bugs can't build resistance to it. It works in two different ways. It is sharp for insects. It cuts and gets caught in the joints of their exoskeleton. It is a desiccant, meaning it dries things out. It turns bugs into little bug jerky.
Paul covers the variance in the grades of DE. There is a food grade version.
So I guess you know that diatomaceous earth slashes earth worms to ribbons, if they were dumb enough to hang around. They aren't, of course, so the earth worms leave, and then there is one fewer amazing soil amender left.
And since diatomaceous earth can't be removed, once it's in place, the earth worms won't come back.
The first person to drink cow's milk. That started off as a dare from this tiny ad:
Binge on 17 Seasons of Permaculture Design Monkeys!