Among the plants growing on the Arboretum’s Terassi (Terrace) was an old azalea shrub, which was selected for propagation and named 'Ruususen Uni' by Marjatta Uosukainen. It was probably planted in the 1930s and is thought to be a double-flowered hybrid originally called ‘Aida’, from the 1800s, belonging to the Rustica group. Now it has a new name.
The azalea’s delicate double flowers are a pastel pink shade. In autumn the foliage turns a magnificent orange or bright red. In ten years ‘Ruususen Uni’ reaches about half a metre.