A small group of tall flowering hardy biennials and short-lived perennials, related to the cabbage family. Easily grown from seed, sweet rocket makes an ideal gap filler in any spacious sunny border.
Family: Brassicaceae (cabbage)
Botanical Name: Hesperis
Common Names: Sweet rocket, dame's violet, dame's rocket.
Foliage: Deciduous, dark-green, pointed leaves.
Flowers: Tall stems topped with loose clusters of white or pale purple flowers. Good evening fragrance.
Flowering Period: June-July.
Soil: Moist but well-drained soil (chalk, clay, sand or loam). Alkaline or neutral pH.
Conditions: Best in full sun, but will tolerate some shade. Can be planted in a north, east, west or south facing aspect.
Type: Hardy biennial/perennial.
Origin: Europe and Asia.
Hardiness: Hardy throughout the UK.
Grow in full sun or light shade, in a moist sandy loam.
Ideal as a cottage garden plant or in a mixed herbaceous border. Sweet rocket will self-seed around prolifically if the growing conditions are good.
Attracts butterflies and other beneficial insects to the garden.
Keep weed free and water well in dry weather.
Deadhead spent blooms.
Susceptible to attack by slugs and snails and other cabbage pests. The leaves can be affected by powdery mildew.
Sow seed outdoors in April-May, in prepared nursery bed. Gradually thin to required spacing and plant out in flowering positions in autumn; ready for flowering the following year.
Perennials can be divided in October-March. However, the plants tend to deteriorate with age so are best grown each year from seed.
The main species available is H. matronalis. Usually sold as mixed seed but single colours are available.
Hesperis matronalis (sweet rocket) bears clusters of four petalled flowers in white, pink or mauve, on slender stems. Height 2ft (60cm) or more. For sale at Thompson & Morgan. Single colour cultivars include: