Dame's Rocket (Hesperis matronalis)
Hand pull: Any time of year when the ground is soft, especially after a rain, hand pull small plants by the base of the stem. Be sure to pull up the entire taproot as sections left in the ground may
Re-sprout. Hang from a branch to prevent re-rooting. If plants are pulled while in bloom bag for garbage or burn since seeds can still ripen and spread. Pulling may need to be done for several years to remove new plants established from the seed bank
Cutting: Flower heads of Dame’s rocket can be cut just after bloom to prevent seed set. Since Dame’s rocket continuously flowers, blooms may need revisiting again in the same growing season.
Low volume foliar spray: This method is used for dense populations and best left to a contractor. Glyphosate containing herbicides can be applied in late fall when native plants are dormant, but the Dame’s rocket basal rosettes of leaves are still green and vulnerable to sprays. Herbicides may be likewise applied in early spring when native plants are still dormant but Dame’s rocket has begun to leaf out
Damesrocket is an herbaceous, biennial forb that grows up to 4 ft. (1.2 m) in height. It is often mistakenly planted in native wildflower mixes. Its alternate leaves are broadly lanceolate and sessile or born on short petioles. Leaves are 2-6 in. (5-15 cm) long and hairy. 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. Habitats invaded include open woodlands, prairies, roadsides, ditches, and other disturbed areas. (www.invasive.org) Often confused with the native Garden phlox. Roughly the same colors. An obvious difference is that Dame's rocket has 4 petals while Phlox boasts 5.
Competes with native herbaceous plants at the edges of woodlands, in woodland openings, and in semi-open forests. This competition for light, moisture, and nutrients may inhibit tree seedling germination and growth.