Blue pimpernel

This is the blue perennial version of the common native annual scarlet pimpernel, although there are varieties such as 'Sunrise' which have bright red flowers, and odd red or pink-flowered seedlings of the wild species sometimes occur. It is a charming and unassuming plant, easily raised from seed if the borderline plants succumb to frost in winter, or cuttings may taken as an insurance for overwintering indoors. Perfect drainage is a sound precaution against loss, while full sun encourages the most prolific display of intense indigo-blue flowers all summer. The Royal Horticultural Society has given it its prestigious Award of Garden Merit (AGM).