Chiri-san Sue Mountain Hydrangea. This charming little Hydrangea was introduced to the gardening world by Dan Hinkley of Heronswood Nursery fame. It was named for the Korean mountain where it was found, "Cheri-san" and fellow plant explorer Sue Wynn-Jones of Crug Farms in Wales. The florets are somewhat double and can be blue or pink depending on the available aluminum in the soil. More Al gives bluer flowers, less gives more pink. It is happiest here in the Southeast with filtered sun, but in the Northwest, where the first pictures were taken near Seattle, it can be grown in full sun because of the lower summer temperatures. This also renders more pigment in the leaves, which one won't see here in the Deep South. We have been struck how it flowers at a very young age. Give uniform moisture for best performance. I am not so sure that it won't take colder temps than zone 7. Many H. serrata selections will grow as far north as zone 5.