Hesperis matronalis has many fragrant clusters of flowers coloured pale lilac to purple produced from may to july it is at its best when grown in large drifts leaving plenty of blooms to spare for early summer bouquetsthe richly scented flowers of sweet rocketwillattract pollinating insects making this an excellent choice for wildlife areas or a herbaceous border hesperis is a biennial or relatively short45lived perennial but it will happily seed about to create swathes of flowers