Dreaming Purple is a compact buddleja, which grows in small mounds. It's foliage is deciduous, with arching stems that hold lance-shaped, green leaves. Cone shaped flower heads appear in summer, covered in tiny purple, fragrant flowers. These last through to autumn.  

At a glance:

Deciduous foliage

Purple flowers appear in summer

Full sun

Well drained fertile soil

Hardy

Will reach a height of 1m and a spread of 1m over 1-2 years