Dame’s rocket

Dame’s rocket: how do you recognise it?

Habit

Biennial or short-lived perennial: first a rosette, in the second year straight, branching stems up to 80 cm, about 40 cm across.

Leaves

Lance-shaped, 5–15 cm, dark green and slightly hairy, with a finely toothed edge.

Flower

Loose clusters at the stem tips, from May to July; each flower of about 2 cm has four petals in a cross.

Colour

Lilac to purple, sometimes white; double-flowered forms also exist.

Scent

Sweet and spicy, strongest at dusk and at night.

Fruit

Long, narrow seed pods full of seed, which split open in summer.

Flowering: May–July · Sowing: April–June · Plants: September–October · Pruning: July

Why grow it?

• A lovely sweet scent, especially in the evening: plant it near a patio or seat.
• Flowers in May–July, between the spring flowers and the summer border.
• Attracts bees, bumblebees and butterflies; the orange-tip butterfly lays its eggs on it.
• Grows in sun or part shade and in almost any garden soil.
• Self-seeds, so you have flowers every year without sowing again.

Dame’s rocket: where does it grow best?

• Sun or part shade; it also does well in light shade at a woodland edge or under tall shrubs.
• Any ordinary garden soil: sand, loam or clay, acid to chalky.
• Moderately moist; in full sun give some water in dry spells.
• Plant 30–40 cm apart, ideally in small groups, close to a patio or window to enjoy the scent.

Light

Sun and partial shade

Soil type

Sand, loam or clay

Acidity

Not fussy

Moisture

Normal

Size

0.8 m tall, 0.4 m wide

Hardiness

Hardy (to -25 °C)

Goes well with

• Columbine: Flowers at the same time and self-seeds just as easily.
• Foxglove: Another biennial for part shade, with tall spikes beside the loose clusters.
• Honesty: Another biennial of the cabbage family: together a lilac spring picture and food for the orange-tip.
• Roses: The lilac haze and evening scent suit old roses in a romantic border.
• Forget-me-not: A blue carpet in May at the foot of dame’s rocket.

Dame’s rocket: when and how to plant it?

Plant in September–October.

1. Sow in April–June, ideally in May–June, thinly where it is to flower or in a seedbed; barely cover the seed.
2. Thin out or prick out the seedlings so they get 30–40 cm of space.
3. Move the young plants to their final spot in September–October; they flower the following year.
4. Dig a hole slightly larger than the root ball and plant at the same depth as before.
5. Firm the soil and water in well straight away.

Care

Watering

Water young plants in dry spells. Established plants manage on their own, except in long droughts.

Feeding

Needs little: a spadeful of compost in spring is enough.

Support

On a windy site or in rich soil the stems can flop: add a few twiggy sticks or a plant support.

Deadheading

Cut off the flower stems after flowering if you do not want seedlings; leave a few if it may self-seed.

Seedlings

Keep a few seedlings every year: dame’s rocket then stays in your garden even when the old plants die out.

Tip: Plant dame’s rocket by a patio, a bench or an open window: the scent only really comes out at dusk. White forms stand out best in the twilight.

Dame’s rocket: when to prune it?

Pruning months: July.

When: After flowering, in July. No other pruning is needed.

How:

• Cut faded stems back to just above the leaves: this stops it seeding everywhere.
• Let a few stems set seed if you want new plants next year.
• Cutting back straight after flowering sometimes lets the plant live a year longer.

Caution: If you let all the seed pods ripen, there will be seedlings all over the border next year.

Pruning: when and how · Pruning calendar and basic rules

Propagation

Seed

Sow thinly in April–June where it is to flower or in a seedbed, and transplant the seedlings in September–October. The seed germinates easily.

Self-sown seedlings

Let a few stems set seed and move the seedlings in autumn to where you want them.

Cuttings

Double-flowered forms do not come true from seed: in spring take cuttings of young shoots at the base and root them in moist cutting compost.

Dame’s rocket: how does it get through the winter?

Hardy to −25 °C.

• Fully hardy, to about −25 °C: no protection needed.
• The rosette often stays green through winter and starts growing again in early spring.
• Waterlogged soil in winter can rot the rosette: choose a well-drained spot.

Diseases and pests

• Flea beetles: Tiny jumping beetles make small holes in the leaves of young plants, especially in dry weather. Keep the soil moist; older plants outgrow the damage.
• Caterpillars: Caterpillars of white butterflies and the orange-tip eat leaves, buds and seed pods. The damage is usually minor; the orange-tip is a welcome guest.
• Slugs: They eat seedlings and young rosettes. Pick them off in the evening.
• Powdery mildew: White powder on the leaves in dry summers. Cut away affected leaves and water during dry spells.
• Dying out: After two or three years the plant often dies. Let some seed ripen every year or sow again.

Through the year

• March: Rosettes start growing. Add compost.
• April: Sow in place or in a seedbed. Put supports in.
• May: Flowering starts. Sow for flowers next year.
• June: Full flower; enjoy the scent in the evening. Sow.
• July: Last flowers. Cut back faded stems or let seed ripen.
• August: Collect seed. Water seedlings in dry spells.
• September: Move young plants to their final spot.
• October: Plant. Transplant self-sown seedlings.

Good for wildlife

Bees

Nectar and pollen for honeybees and wild bees.

Butterflies

Nectar for butterflies.

Did you know?

• The name Hesperis comes from the Greek hespera, ‘evening’, after the scent that is released mainly in the evening.
• You can tell it from phlox, with which it is often confused, by the flower: four petals instead of five.
• It is a food plant of the orange-tip butterfly: the butterfly lays its eggs on the flower stalks and the caterpillars eat the seed pods.