Aster divariticus: Masses of white, daisy-like flowers with brownish yellow centres in loose clusters from June to October. This white wood aster, originally from North America, was a favourite of Gertrude Jekyll's.
Nepeta racemosa 'Walker's Low' Deep violet to lilac-blue summer flowers and aromatic mid-green leaves. This violet-lilac catmint makes excellent, long-flowering, groundcover for a sunny border. Clipped back after the first flush in June, it flowers through to early autumn. Useful as an informal, scented edge for paths as, when trodden on, the foliage releases a pleasant aroma.