Campanula lactiflora 'Alba' (Milky bellflower 'Alba'): Tall stems with clusters of pure white flowers in mid-summer. Ideal for filling out borders and adding height. Hardy. Up to 1.2m

Campanula persicifolia (Peach-leaved bellflower): Tall spikes of large, cup-shaped blue flowers over slender foliage in mid-summer. To 1.2m. Hardy

Monarda 'Prarienacht' (Bergamot 'Prarienacht'): Whorls of zingy purple flowers over bright green aromatic foliage. Very attractive to bees. Hardy. Up to 90cm.