I am fascinated with the changes in my blue hydrangea. I have also enjoyed seeing other bloggers posting their ever changing hydrangeas. The first collage tracks the hydrangea during the early part of the season and the second one is the latter part of the blooming season which brings me to the present. You can click inside the collages to enlarge them.
I understand the process in theory although I'm confused by why my hydrangea in recent years makes this change during a single growing season without my doing anything to bring it about. The process is explained well on this hydrangea questions and answers page. In brief, acidic soil produces the blue blossoms on large leaf hydrangeas and neutral to alkaline soil produces pink blossoms. However, that doesn't explain why my blossoms change colors during the season without my doing anything to change the pH. I guess it may be one of life's mysteries but if anyone knows the answer, I would appreciate your sharing it with me.