Hesperis matronalis Seeds | Dame’s Rocket
LATIN NAME: Hesperis matronalis
COMMON NAME: Dame’s Rocket
Plant Profile
Dame’s rocket is a biennial or short-lived perennial of sixty to ninety centimetres, with lance-shaped leaves and loose heads of four-petalled flowers in violet, mauve or white. It flowers in late spring and holds its scent into the evening, which is when the moths that pollinate it are flying.
The four petals are the giveaway that separates it from phlox, which has five and flowers later. It is a plant of hedgerows and damp meadows from England to the Caucasus, and it has escaped from gardens across North America, where it is now listed as invasive in several states. The leaves are toothed and slightly hairy, and the basal rosette stays green through winter in all but the hardest frost.
Science & Biotechnology
The species is self-incompatible, so a single plant sets little seed and a group sets a great deal. The flowers are protandrous: the anthers shed pollen before the stigma of the same flower is receptive, which enforces outcrossing even within a spike.
Its spread in North America follows roads and rivers, and it forms dense stands in woodland edges where it displaces native spring flora. Several states restrict its sale, and the plant is a good example of a species that is a wildflower at home and a weed abroad, with no change in its biology.
Uses & Benefits
It is grown for cut flowers and for the evening scent, and it is one of the few tall plants that will flower in light shade. The single-flowered forms last a few days in water; the double forms last longer and smell less.
The young leaves are edible and peppery, used in salads in the same way as rocket, though the plant is not grown for food and the quantity eaten should be small. The seed is produced in long thin pods that shatter as they ripen, which is how the plant moves around a garden. The white form and the double form are sold as named plants, and the double flowers last a week in water rather than three days.
Growing from Seed
Sow in early summer for flowers the following spring, since the plant needs a cold winter to vernalise. Surface sow, since light helps germination, and thin to thirty centimetres. A spring sowing will give leaf rosettes and no flowers until the next year.
Cut the flower stems after the first flush to encourage a second, and pull the plant out after seeding if it is not wanted everywhere. In a wild garden leave a few pods to ripen and it will place itself better than any plan. It tolerates damp soil and part shade, and it is short-lived, so keep a few seedlings coming on.
Our Take
A sweet-scented biennial for the back of a border and for evening, and a plant to deadhead if you garden near woodland. Sow it in summer, not in spring.
Related Reading
More species in the same orbit as Dame’s Rocket: