Dame's Rocket
(Hesperis matronalis)

Damesrocket is sold occasionally by local nurseries and
can also be found in “wildflower” seed mixes. This garden bully has
escaped cultivation and become a problem throughout Colorado, including
the Boulder foothills area. It readily invades steep slopes and riparian
areas, as well as disturbed ground. Damesrocket is a native of Europe
and can be classified as either a biennial or perennial. The stems can
grow up to 4 feet tall, with purple flowers that appear from April through
July. Alternatives to planting Damesrocket, include Colorado Columbine
(Aquilegia caerulea) and Lavender Native Bee Balm (Monarda fistulosa
menthaefolia).