here it is
"There are certainly many control methods offered by specialists and others who
claim success in killing this weed. If you’ve been around older farmers who
follow moon signs, then you might have heard this one: “Mow Canada thistle when
the (zodiac) sign is in the heart and they will bleed out and die”.
Well, unfortunately there isn’t research to back up this method. Some
specialists offer that a combination of practices including mowing, tillage and
herbicide application can effectively control Canada thistle. Other ideas have
been researched including planting Sudangrass in early June as a summer cover
crop in areas heavily affected by Canada thistle. There is on-going research by
the University of Illinois with northern Illinois farmers planting Sudangrass.
Findings from this study are that the Sudangrass out competes Canada thistle
because it grows taller and basically smothers it .
Weed scientists do agree that an herbicide application to control Canada
thistle is most effective in the fall. This is because the plant is looking to
recharge its root system for a flush of growth around the time of the first
frost. A systemic herbicide with active ingredients such as glyphosate, 2,4-D,
dicamba, or aminopyralid applied at this time will move to the same plant parts
as the carbohydrates needed for growth.
Some recent research suggests that fall applications of herbicides to control
Canada thistle can wait until late October or early November. Mark Loux, an
Ohio State University Extension specialist, feels that herbicides are most
active after a frost with perennial weeds. He notes that Canada thistle should
be 8 to 12 inches tall when applying herbicide in the fall (Ohio State C.O.R.N.
Canada thistle is making a comeback even though glyphosate seemed to wipe it out for awhile. It hasn't been this heavy since we started using Basagran to control thistle 30 years ago.
I have a bunch to wipe out so I've been reading up on it and thought it might make a good topic today.