Siberian rocket.

At a glance

Care level

Easy

Plant type

Perennial

Light

Partial shade to full sun

Indoor light

Bright indirect

Water

Every 3 to 7 days

Mature size

3 feet

Growth rate

Medium

Hardiness

USDA 3 to 8

Bloom time

Late spring to mid summer

Care

Keep the soil consistently moist but not waterlogged to support healthy blooming. Watch for wilting leaves which often signal that the plant needs a drink. Deadhead spent flowers to encourage a second flush of blooms.

Watering

Water when the top inch of soil feels dry to the touch.

Feeding

Apply a balanced liquid fertilizer during the active growing season.

Pruning

Trim back faded flower stalks to keep the plant tidy and encourage new growth.

Repotting

Move to a slightly larger container once the roots begin to crowd the pot.

Soil

Well draining loamy soil

Soil pH

6.0 to 7.5

Temperature

-30 to 25°C

Humidity

40 to 70%

Drought tolerance

Moderate

Lifespan

Short lived perennial, typically 2 to 4 years.

Fragrance

Strong

Deer and rabbits

Moderate

Safety

People

The plant is generally considered non-toxic but may cause mild stomach irritation if ingested in large quantities.

Children

Keep away from small children as the seeds can be a choking hazard.

Contact allergens

The foliage can cause mild skin irritation in sensitive individuals.

Airborne allergens

The flowers produce a sweet scent that may trigger mild hay fever in some people.

Edibility

While often listed as edible, the seeds and foliage can cause digestive upset in some people and should be avoided.

How to identify it

• Clusters of fragrant purple flowers
• Lance shaped toothed leaves
• Upright branching stems
• Four petaled cruciform flowers

Height

0.4 to 1m

Spread

0.3 to 0.45m

Leaves

green, deciduous

Flowers

purple, lavender, white, 1 to 2cm

Fruit

brown, late summer

Problems to watch for

• Powdery mildew · A white fungal growth on leaves often caused by poor air circulation.

Growing it

Propagation

seed

When to plant

spring, autumn

Overwintering

Cut back the dead foliage in late autumn to keep the garden tidy. A light layer of mulch helps protect the crown during harsh freezes.

In containers

It grows well in containers at least 30 cm deep with good drainage.

Plant in groups to create a drift of color that attracts pollinators to your garden.

Grows well with

• Columbine · They share similar light and moisture requirements in woodland settings.
• Ferns · The contrasting textures look beautiful in a shaded border.

Similar species

• Dame's Rocket · A very similar looking plant that is considered invasive in many areas.

Science

Family

Brassicaceae

Genus

Hesperis

Order

Brassicales

Class

Magnoliopsida

Native range

Northern Asia and parts of Eastern Europe.

Conservation

Not currently of conservation concern.

It grows naturally in moist meadows and along forest edges where it benefits from dappled light.

Value to wildlife

nectar source

Pollinators

bees, butterflies, moths

Uses

cottage gardens, pollinator gardens, woodland borders

Taxonomy resolved against GBIF.

Questions people ask

Is this plant invasive?

It is much less aggressive than Hesperis matronalis but should still be monitored.

Does it need full sun?

It prefers partial shade but will tolerate full sun in cooler regions.

Where the name comes from

The genus name Hesperis comes from the Greek word for evening, referring to the scent of the flowers, while sibirica denotes its Siberian origins.

Good to know

• It is closely related to the common Dame's Rocket.
• The flowers are notably fragrant in the evening.
• It thrives in cooler climates where other species might struggle.