Pee gee hydrangea is the shrub that all the familiar autumn hydrangeas have been developed from. Reaching 4 metres in height, shrubby or sometimes tree-like, this species has creamy-white flowers in conical clusters. In addition to the small fertile flowers they also have a showy border of sterile flowers with large sepals instead of reproductive organs.
Some of the varieties developed from pee gee hydrangea have a large number of sterile flowers in the outer ring, while some have only these sterile flowers, and they are unable to produce seed. The variety ‘Grandifolia’ is one of these. In past decades it was among the most popular garden shrubs in Finland. Mustila’s own namesake variety (H. paniculata ‘Mustila’) closely resembles in outward appearance the natural pee gee hydrangea.
In addition to the ‘Mustila’ variety, there are also true young pee gee hydrangeas growing at the Arboretum, from natural seed collected on Hokkaida and the Kurile Islands. In recent years about 40 pee gee varieties have been planted to discover which of them are best suited to Finnish conditions. The species is a valuable addition to Finnish gardens, flowering as it does in late summer and autumn when very few other shrubs are in flower.