Clematis armandii or Armand clematis is a white blooming and very prolific clematis that flowers in spring but can produce more flushes of fragrant flowers throughout the summer.
Being a fast grower it will need good support from a large trellis, arch, shed or just let it scramble up an old tree.
Though the higher it gets the higher the blooms (out of sight) and this is what you plant them for.
This is a fairly rugged plant that will survive mild drought conditions but it does need cool roots so keep them shaded.