My version of this book calls for seeding okra in flats or broadcast at 1" and then thin to 12" in the bed. But the spacing is never explained in the book and I think in practice much of the spacing guidelines were never empirically tested. And when I reference them with spacing recommendations for SC from Clemson, many of them aren't much different. I typically stick to Clemson's guidelines and not what's in the book. I use this book as a very rough guide for doing biointensive.