There's an old gardening myth that you can turn hydrangeas blue by burying pennies or nails in the soil. Unfortunately, this particular wisdom isn't true, but there are other ways you can change these ...

Closeup of the bright blue blooms of a mophead hydrangea - Kenwiedemann/Getty Images Hydrangeas are as fascinating as they are beautiful. The blooms of certain varieties act as a litmus test of the ...