AgapanthusAgapanthus Agapanthus 'Su Casa' In midsummer, when most border plants are starting to flag, the agapanthus is just getting going. Tall, bare stems rise above clumps of strappy leaves and open into perfect spherical heads of trumpet shaped flowers in deep, rich purple. It's a bold, reliable performance that keeps going for weeks. Native to South Africa, agapanthus is more suited to UK gardens than most people expect. 'Su Casa' is a deciduous variety it