Dame's Rocket

Fact SheetHesperis matronalis

Invader Images

    • Dame's Rocket Flowers
      Dame's Rocket Flowers
    • Dame's Rocket Infestation
      Dame's Rocket Infestation
    • Dame's Rocket Stems and Leaves
      Dame's Rocket Stems and Leaves

Common Look-alikes

    • Downy phlox, five petals versus four
      Downy phlox, five petals versus four

Identification

Appearance

Hesperis matronalis is a herbaceous, biennial forb that grows up to 4 ft. (1.2 m) in height. It may be included in native wildflower mix packets. Always check the list of species in wildflower mixes.

Foliage

The alternate leaves are broadly lanceolate and sessile or born on short petioles. Leaves are 2-6 in. (5-15 cm) long and hairy.

Flowers

The showy, fragrant flowers vary in color from white to purple or pink and develop in the late spring. Flowers develop in clusters on 3 ft. (1 m) tall stalks.

Fruit

The siliques (long slender fruits) are 2-4 in. (5-10 cm) in length and contain a large number of seeds.

Biology

This species is considered a watch list species.

Origin

Native to Europe

Habitat

Early successional forest, edge, floodplain forest, herbaceous wetland, open disturbed area, pasture,  roadside, wacant lot, wet meadow, yard or Garden. Hesperis matronalis is frequently found in riparian or wetland habitats, as well as rich open woods. It is also found along roads and in gardens, where it is still planted.

Life cycle

Dame’s rocket generally produces a basal rosette the first year and flowers the following year. The plants are prolific bloomers and produce large quantities of seed from May through July. Individual plants may have several clusters of flowers at various stages of development, enabling the plant to produce both flowers and seeds at the same time.

Ecological Threat

Many people mistakenly believe Hesperis matronalis is a native wildflower. It may be included in native wildflower mix packets. Always check the list of species in wildflower mixes. Habitats invaded by this plant include open woodlands, prairies, roadsides, ditches, and other disturbed areas where native plants are crowded out. Hesperis matronalis was introduced from Europe as an ornamental around the time of European settlement. It continues to be widely used as an ornamental and can be found throughout North America.These plants crowd out native vegetation with their great numbers of seeds.

Management Options

Mechanical Control

Pulling or use of a dandelion digger is most effective when the soil is moist is effective. Flowerheads should be bagged for landfill, or dried and burned where permissible. Where there is sufficient leaf litter or other fuel, burning has been found to be an effective control method.

Chemical Control

It can be effectively controlled using any of several readily available general use herbicides such as glyphosate. To avoid damaging adjacent native vegetation, apply herbicide in late fall when the rosettes are still green. Follow label and state requirements.

  • Be careful not to damage or kill nearby native plants when conducting management work. And when using herbicides, always follow the instructions on the label.

 

Citations

Photo Credit

Dame's Rocket, UGA5450195, UGA5450174, UGA5450136, Leslie J. Mehrhoff, University of Connecticut, Bugwood.org

Information Credit 

Go Botany, Hesperis matronalis

Invasive Plant Atlas of New England

U.S. Forest Service 

Colorado Weed Management Association