Eupatorium purpureum 'Little Red'

Specially imported from USA by us, this  deep red variety was sold to us as a shorter form than the 'Atropurpureum' more commonly seen in this country, however, after 3 or 4 years growing in good damp conditions it has reached the same six-foot heights as 'Atropurpureum' in our garden! It will, however, grow short (about 3 feet) in the first year or two. then need dividing to keep it compact.