Dames Rocket - Hesperis matronalis

Dame’s Rocket is part of the mustard family (Brassicaceae). It is a tall, biennial or short-lived perennial (due to aggressive reseeding) that can grow up to 2 or 3 feet tall. The first-year plants overwinter as an evergreen basal rosette.

Description

Flowers: Flowers range in color from white to pink and purple. They are borne in terminal clusters and can be quite fragrant with a clove-like aroma. Dame’s rocket is sometimes mistaken for phlox species, but flowers have four petals while phlox has five petals.

Leaves: Leaves are lanceolate or ovate-lanceolate with dense hairs and finely toothed margins. Leaves usually become progressively smaller as you move up the stem and are alternately arranged along the hairy stem. This is another characteristic that sets it apart from phlox. Phlox leaves are arranged oppositely along the stem (directly across from each other).

Seeds/fruit: Dame’s rocket also produces a silique. The fruit ripens from June to August and dehisces in late summer to release thousands of seeds.

Distribution: This species has been documented in 44 counties within the state of Michigan. It commonly grows along roadsides and other disturbed sites but spreads readily to adjacent woodlands and wetlands where it is ecologically invasive.

Blooming period: Begins flowering in mid-May and lasts through July.

Native status: Exotic/introduced. This species is not native to the United States.

Garden uses: Dame’s rocket is listed as a noxious weed in several states and should not be planted in the garden due to its invasive tendencies.

Management: Dame’s rocket can spread aggressively at sites due to prolific re-seeding. Efforts can be made to hand pull the mature plants before seeding to prevent further spread. Control efforts should be in place for several years until the seed bank has been exhausted.

Common look-alikes: Wild blue phlox (Phlox divaricata), prairie phlox (Phlox pilosa) and perennial phlox (Phlox paniculata)