What do you add to the soil to get the beautiful blue hydrangea color found on Cape Cod?
He did a whole segmant on his show about the coloring of hydrangeas and explained how the ph of the soil affected the color. Acid causes one color and alkiline produces the other (pink or blue). Sorry I don’t remember which produces which. I do know if you have acid soil and want to reduce it, use lyme. But P.Allen Smith does have a web site and if the info is not directly there, I believe you can email a question. The website: http://www.pallensmith.com/ You might also try this website: http://davesgarden.com/ Sources: http://davesgarden.com/ http://www.pallensmith.
