Salvia 'Mystic Spires Blue':
Frost tender perennial with tall vibrant purple flowers in late summer and contrasting dark green foliage. Long flowering. Up to 1m.
Sporobolus heterolepsis (prairie dropseed):
Fine deciduous grass with green foliage in summer turning golden. Graceful flower heads in late summer. Needs sunny spot in well-drained soil. Hardy. Up to 1m.