Perennials: Phlox, 1 by Carolyn22

Carolyn22 wrote:
A number of years ago, I planted P. Starfire and P. Franz Shubert rather close together. They have lived together harmoniously for quite some time. I was very surprised this year to see a lighter pink with a darker pink ring growing between the 2 phlox I have had together for quite some time. I don't have any plain pink phlox in my garden, so I have to beleive they have somehow cross polinated and seeded itself. Any other ideas on this?