Growing Guide
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Dame’s Rocket

Herbaceous Biennial Flower, Wildflower

Also known as Sweet Rocket, Dame's Violet, Wild Phlox
Hesperis matronalis
Brassicaceae Family

This attractive non-native has phlox-like purple or white flowers. It is a biennial, but behaves like a perennial because it is an aggressive reseeder. Some consider it an invasive species, especially in wet sites with rich soil.

Site Characteristics
  • full sun
  • part shade
Prefers part shade.

Soil conditions:

  • requires well-drained soil
Prefers rich, moist but well-drained soil with neutral to alkaline pH.

Hardiness zones:

  • 4 to 9
May be marginally hardy in Zone 3.
Plant Traits

Lifecycle: biennial

Biennial or short-lived perennial. Behaves like a perennial due to aggressive reseeding.

Ease-of-care: easy

Height: 2 to 3 feet

Spread: 1.5 to 2 feet

Bloom time:

  • late spring
  • early summer

Flower color:

  • violet
  • white

Foliage color: medium green

Foliage texture: medium

Shape: upright

Shape in flower: flower stalks with upright spikes

Flowers borne in dense clusters above the foliage.

Special Considerations
Special characteristics:
  • aggressive - Self-sows prolifically.
  • invasive - Has naturalized in North America and is now commonly considered a wildflower. Considered a noxious weed by New York State.
  • not native to North America - Native to Europe east to Siberia and China.
  • fragrant
  • beneficial insects - Flowers attract moths.
Special uses:
  • cut flowers - Double-flowered varieties in particular.
  • wildflowers
Growing Information
How to plant:

Propagate by seed, cuttings, division or separation - Start the seeds outdoors where desired at any time from spring until two months before the first heavy fall frost. Do not cover, as light aids germination.

Propagate double-flowered forms by division or terminal cuttings.

Days to emergence: 21 to 28

Maintenance and care:
Cut back to basal foliage after flowers fade to prevent self-seeding.

May require staking.

Keep soil moist but not soggy.

More growing information: How to Grow Perennials

Flea beetles
Slugs and snails
var. albiflora - White flowers. Breeds true if isolated from plants with colored flowers.

var. albiflora 'Alba Plena' - White double flowers on 1 ½ to 2’ tall plants.

'Lilacina Flore Pleno' - Double lilac flowers.

'Purpurea Pleno' - Double purple flowers.