Snapdragon

True to its name, the flowers are pure white, being set off by the clear green foliage. Keep deadheading and they'll last right through summer, into autumn. Seed can be sown in late summer or early autumn, pots being kept in a cold frame over winter, or wait until early spring. The plants look best when planted in clusters in a cottage garden or informal border, making a strong contrast with rich reds and blues.

Looks good with:

Festuca glauca
Heuchera micrantha var. diversifolia 'Palace Purple'