New invasive weeds
Common tansy was recently identified along a roadside in northeast South Dakota. This weed has been well established in western Minnesota for several years, so it is not too surprising to see it in eastern South Dakota, says Mike Moechnig, South Dakota State University Extension weed specialist.
This common tansy is not yet widespread, but it has the potential to be invasive, so watching for this weed and controlling patches while they are small is critical, according to Moechnig.
• Common tansy is a new weed to eastern South Dakota.
• Oxeye daisy is a problem in western South Dakota.
• Control these weeds while they are still in small patches.
Common tansy has already spread extensively in the Black Hills and is designated as a local noxious weed in Lawrence and Pennington counties.
Common tansy is a perennial that can spread by seed or roots. Livestock will generally avoid grazing it due to its bad taste, but there are some reports that it can be toxic if consumed in large quantities over an extended period of time.
Oxeye daisy was added to the list of potential local noxious weeds in South Dakota this year. It will likely only be designated as a noxious weed in counties that include the Black Hills, Moechnig says.
Oxeye daisy also is established in eastern South Dakota, but it does not seem to be as invasive as in the west.
“It seems to persist around my house just north of Brookings but patches never become dense enough to suppress grass growth,” Moechnig says. “This plant produces large flowers so it is tempting to not control it, but it may be important to monitor populations and take action to prevent it from spreading to neighboring properties.”
For SDSU Extension recommendations of herbicides to control common tansy, oxeye daisy and other noxious weeds, go online to www.FarmProgress.com and click on “Noxious Weed Control in South Dakota” under Web Exclusives.
Source: South Dakota Pest Report
This article published in the September, 2012 edition of DAKOTA FARMER.