Every spring, the same advice pops up in garden forums and neighborly chats: Toss a few rusty nails into the soil when you plant. The promise varies—bluer hydrangeas, greener houseplants, better ...

The Rusty Nail is, in a word, dated. And yet, there’s something about the Rusty Nail we just can’t quit. Maybe it’s the name—to me it sounds like some creatively defined sex act, but there’s obviously ...