Hesperis Purple (Sweet Rocket)

Hesperis matronalis ‘Purple’ Sweet Rocket / Dame’s Violet ‘Purple’

The classic violet-purple form of the great evening flower tall 7590cm branching stems clothed in loose clusters of four-petalled flowers in rich velvety violet-purple, releasing a powerful sweet violet-and-clove fragrance as darkness falls. Hesperis ‘Purple’ is the cottage garden classic that brings dusk-scented romance to shaded borders and serves as the preferred larval food plant for the Orange Tip butterfly.

This is the iconic form of Sweet Rocket the variety that has filled English cottage gardens with evening fragrance for centuries. The rich vibrant violet-purple flowers are beautiful during the day but transform at dusk when the powerful sweet scent fills the surrounding air. The fragrance has a particular depth violets and cloves combined that few other plants can match, and the timing (evening release) is biologically tuned to attract night-flying moths. Hardy biennial (H7) following the two-year rhythm: rosette in Year 1, flowering glory in Year 2, then dies (but self-seeds reliably for permanent colonies). RHS Plants for Pollinators recognised. Preferred larval food plant for the Orange Tip butterfly making ‘Purple’ Hesperis one of the most ecologically valuable plants in any wildlife cottage garden.

A note on growing

Sow direct outdoors MayJuly (or in modules indoors at 1518C). Cover seeds lightly with 35mm fine soil. Germination 1421 days. Move plants to their final positions in October partial shade or sun in moist humus-rich soil. Hesperis ‘Purple’ is genuinely most reliable in partial shade where soil moisture stays consistent through summer. The wild form grows along damp woodland edges and hedgerows replicating these conditions in the garden gives the best results.

Cutting tip: cut when approximately one-quarter of the florets on each stem are open with the rest still in bud the stem continues opening in the vase over several days. Re-cut stems at an angle and place immediately in deep water. Strip leaves below the waterline.

Self-seeding management: Hesperis self-seeds prolifically in suitable conditions so prolifically that if allowed to set seed unrestricted in a small garden, it can become overwhelming. In small spaces, deadhead a proportion of plants after flowering to control spread. In larger gardens and woodland-edge plantings, let the colony establish naturally.

About Cabbage White caterpillars: as a Brassicaceae member, Hesperis can be targeted by Cabbage White butterfly caterpillars in late summer check leaf undersides from July and hand-remove if needed.

Where it shines

In dusk-scented seating areas plant near benches, patios or open windows where the evening fragrance can drift indoors. In shaded woodland borders. As a self-seeding informal colony plant. In wildlife gardens where the Orange Tip butterfly larval value is genuinely important. As a cut flower for romantic, slightly wild cottage arrangements.

Plant alongside

For the classical complementary colour pairing, combine ‘Purple’ Hesperis with Geum ‘Lady Stratheden’ (yellow) and Foxglove ‘Primrose Yellow’ yellow and purple are complementary colours that intensify each other, and all three flower simultaneously in MayJuly. For an all-shade Brassica family combination, pair with Honesty (Lunaria) for the classic biennial partnership. For a “moon garden” pure-white-and-purple scheme, combine with Hesperis ‘White’.