Dame’s rocket on the move

dame's rocket (Hesperis matronalis)
dame’s rocket (Hesperis matronalis)
dame's rocket escaping

dame's rocket, a sleeper weed, escaping cultivation in Wind River Canyon

 

As I was driving through the Wind River Canyon this week, I saw showy purple flowers along the roadside. I stopped to take a closer look and found dame’s rocket moving out of what appeared to be a flower bed, across the road, and down toward the river. The species has been widely planted as an ornamental and has been treated as relatively benign. It certainly seems to be moving unaided in this situation. It is a short-lived mustard that may form dense stands and compete with native vegetation. The species has a building reputation as an invader to be reckoned with in many states: http://www.agannex.com/weeds/dames-rocket-experiencing-explosive-growth-of-an-invasive-weed. This is the first time I have noticed this patch moving outside the area where it was planted. Keep an eye out in your area for any escapees, those showy flowers are easy to spot at highway speed.

 
Unfortunately, many of our invasive weed problems were intentionally introduced as ornamental or forage species. Intentional introductions, subsequent improvement through breeding, and human-mediated establishment of many populations has led to quicker rates of spread than would have happened by natural dispersal alone.

 

Comments

  1. There is no doubt Dame’s rocket is moving from where it was planted. Not just roadsides either, but “natural areas.” I’ve been watching this plant expand every year since I first noticed it in a place it shouldn’t be near Jackson. We declared it a noxious weed to keep an eye on it, but I’m starting to think it’s time to do more than just keep an eye on it.

  2. Brian, I have this in abundance in my back yard gully. I tried Escort on it because it is a mustard. That did not work very well. It is an annual? Maybe there is good seed dormancy. Easy to kill, hard to get rid of. Shade tolerant. Lars

    1. Lars,
      It is chassified as a “short-lived” perennial, which is a little ambiguous, but indicates something more than an annual growth habit. I haven’t found any citations for it spreading vegetatively, but only by seed. As far as control, I, like you, would have first gone to metsulfuron or chlorsulfuron because of their activity on mustards. CSU has both of them listed as chemical options for control of dame’s rocket, but they also note that they have no data to support those recommendations – but research is under way apparently. Based on your comment and Aaron’s perhaps this is one species we should start focusing on a little more in WY if we truly intend to practice EDRR.

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