Probably one of the top ten border plants, this traditional lavender-blue aster offers several advantages over other Michaelmas daisies. It has a longer flowering season, beginning earlier, in mid summer, and continuing into autumn. It doesn’t need staking (except in windy gardens), and is mildew-resistant. It’s also exceptionally free flowering, with an attractive colour that is easy to place as it associates well with so many summer and autumn flowers. Asters are best grown in a sunny or partially shaded position with fertile, well-drained soil. It requires adequate moisture throughout summer. The Royal Horticultural Society has given it its Award of Garden Merit.