Blue Hydrangea

Blue Hydrangea is very popular along the coast of Massachusetts and the islands of Nantucket and Martha's Vineyard. I believe the salty air helps the color to be strong, but I'm not sure. This type of Hydrangea is native to Japan and/or Korea, and was brought over to the US a couple hundred years ago. I've heard that if you put rusty nails around the roots the color will be stronger.