Agapanthus inapertus

From South Africa, an attractive agapanthus as I personally don't like the plain, common ones. It is non invasive*, slow growing and a delightful plant. The flowers are compact, drooping and deep violet blue at about 1.5m.  Deciduous, dry in winter is fine, so are frosts and rain. Drought tolerant too. Full sun is best, but happy in a overcrowded border.  *Doesn't seed here anyway. 

Andrew Massyn, Public domain, via Wikimedia Commons