Hydrangea

Hydrangea are interesting plants. The colour o the flowers depends on the pH of the soil and it's possible to manipulate their colour by adjusting the pH. Sometimes, the flowers from a single plant can show multiple colours, like this one does.

This bush is over 5 years old, and well-established. It's been producing more pink flowers each successive year, but for the moment, it's very interesting to see a spectrum of blue, yellow and pink all on the same plant.