A perennial from Europe, dame’s rocket (Hesperis matronalis) grows 2 to 3 feet tall, with purple, pink, or white blossoms. It was likely brought here as a garden flower, and has been sold in wildflower seed mixes.
It invades fields and field edges, crowding out native plants.
Try hand pulling for small populations; the entire taproot must be removed or the plant will re-grow. Cutting or mowing can prevent seed production and spread. A systemic herbicide applied as a foliar spray can be effective. Herbicide is best applied to the basal rosettes (low round clumps of leaves) in late fall or early spring, when other plants are dormant. Always read and follow the directions on the label when using herbicide.