One of my fellow Wild Ones members commented to me the other day that they had spent an hour each morning before going to work deadheading Dame’s Rocket (Hesperis matronalis) from the very, very steep retaining wall along side their home until she had filled five large garbage bags with blossoms. She was grateful to learn that Dame’s Rocket is a biennial and therefore the remaining plant should now die and leave its roots to help maintain the hillside until native plants are transplanted to take their place.
Another member wrote recently that she had been to a local non-profit organization’s plant sale where they had potted Dame’s Rocket for sale. She knew this was a no-no, but needed some details to pass along to the non-profit organization. Dame’s Rocket is on the Wisconsin’s noxious weed list. It’s restricted. “Restricted species are also subject to a ban on transport, transfer and introduction, but possession is allowed, with the exception of fish and crayfish.” Go to NR 40 for complete details.
There is no doubt Dame’s Rocket is a beautiful blooming plant, but it is terribly aggressive when sharing its seeds and soon takes over precious ground which could be growing beneficial native plants for our wildlife. Planting native phlox (Phlox divaricata, P. glaberrima, P. pilosa) would be a far-better choice.
CONTROLLING DAME’S ROCKET
“Check any “wildflower” seed packets you may purchase to ensure that they do not contain dame’s rocket seeds. You can cut the flower heads off established plants after bloom so the plants do not set seed, or hand pull the plants. If plants are pulled while in bloom, do not compost them, as the seeds can still ripen and spread. Bag the plants for landfilling, or burn them. Do not allow the plants to dry before burning, as seedpods may burst open and spread seeds when dried. If appropriate, burn infested areas where allowed. Finally, glyphosate-containing herbicides can be applied in late fall when native plants are dormant, but the dame’s rocket basal leaf rosettes are still green and vulnerable to sprays. ” (UWEX.EDU)