Pink Hydrangea Flowers June 2013

Pink hydrangea flowers blooming in Louisville, Kentucky, USA (June 2013).

Pink Hydrangea

Pink hydrangea flower blooming June 2010 in Louisville, Kentucky.

Pink Hydrangea

Our hydrangeas are really blooming this year. Last year, a late April frost killed off a lot of the blooms but this year was a very moderate spring.

I believe these flowers reflect the pH of the soil where blue means acidic, white is neutral, and pink is alkaline. So this soil is more alkaline. I might attempt to change the pH of the soil around one plant and see if changes to white, blue or purple.