These have flowers that last weeks and weeks rather than days and days - often flowering more than one a year:

Recommended Essentials:

Aloe aristata

Aloe striatula

Arbutus andrachnoides

Arbutus glandulosa

Azorina vidalii

Beschorneria yuccoides

Cortaderia richardii

Cortaderia sellowiana 'pumilla'

Eucomis bicolor

Fatsia japonica

Fremontodendron 'Californian Glory'

Libertia formosa

Ligustrum delavayi

Ligustrum lucidum

Myrtus apiculata

Strelitzia reginae

Trachelospermum asiaticum

Trachelospermum jasminoides

Trachycarpus fortunei

Viburnum tinus