Thistle epidemic... how to handle?

dragoneggs · Oct 10, 2013

AchingBack said:
Pic #1 does look like Canada thistle, . #2 appears to be bull thistle, which is a biennial, and much easier to control, as it does not regenerate through its roots. Sorry to say, #3 also looks like canada thistle, and number four is also bull thistle. Bull thistle is easily controlled in small areas by beheading. The Canada thistle is going to be your biggest challenge. It has been there forever, hidden in the black berries. The root system is massive. http://www.btny.purdue.edu/pubs/ws/canadathistle/roots.jpg Somewhere I read the average infestation laid flat would cover ten square miles.

Hey AchingBack... I can relate. No cartilage just below my 5th lumbar but that is another story. Thanks for your analysis. But I have to say that I think there is some difference between #1 and #3. I know the pics aren't as helpful as they could be but #1 is shorter and all over. #3 with purple blooms is bigger and not so present. Also #1 never bloomed in purple. Much smaller whitish flower. Do you still say Canadian? Very curious. I also have to say that I have seen #4 alot and it is prevalent here, but I have never seen the prickly balls like #2. Here is another #2 (boy that sounds bad)... note that the foliage is different than #4.

Ken · Oct 10, 2013

dragoneggs said:
Okay pics... upon closer inspection I have found several species, or however you might label them.

View attachment 340798 View attachment 340799 View attachment 340800 View attachment 340801

The most prevalent is the first one and they are normally 18in to 36in. and notice that they are mostly dead some still kicking though... we have had a couple near freezing nights and I am guessing that the cold is doing them in. Easy to pull but I suppose too late. Did spend a couple hours this afternoon wasting my time with them.

The second pic I only found one of but very unusual. I showed the wife and asked her if we should keep it and she said, WHAT?.

The third pic is of the biggest upto 4ft tall but not too many of them.

The fourth is a low growing type and I have left them alone for now. Just no fun to pull by hand. They are intermixed with a couple blackberry varieties.

What I have is picture #3
and fast growing seems to like growing close to tree stump[ or rock so cannot mow easily.
brought in by hired dozer to clear field.
ken

AchingBack · Oct 10, 2013

dragoneggs said:
Hey AchingBack... I can relate. No cartilage just below my 5th lumbar but that is another story. Thanks for your analysis. But I have to say that I think there is some difference between #1 and #3. I know the pics aren't as helpful as they could be but #1 is shorter and all over. #3 with purple blooms is bigger and not so present. Also #1 never bloomed in purple. Much smaller whitish flower. Do you still say Canadian? Very curious. I also have to say that I have seen #4 alot and it is prevalent here, but I have never seen the prickly balls like #2. Here is another #2 (boy that sounds bad)... note that the foliage is different than #4.

View attachment 340819

I agree, #2 doesn't look like bull thistle. The buds aren't the right shape. Perhaps this chart will help identify your plants. Browse Plants by Type: Composite | Wildflowers of the Pacific Northwest