thistle: mow or spray

[skywaterbanjo]

This is awesome information. Thanks.

I will most likely mow 4-5 times for several years and see if I can 'stem' their growth. It is a vacant lot so I don't care that nothing grows on it.

 

[AchingBack]

I've been fighting my infestation of canada thistle for the past 30 years. Did you know, the average infestation has a root system 10 miles long? As was pointed out in an earlier post, the root system is quite deep, and runs vertically, and horizontally in several directions.

I have mistakenly rototilled, (bad idea), mowed, pulled, and sprayed. Decapitation, below the surface, and spraying in the fall when the plant is pulling energy into the roots works well. I haven't used any herbiced other than glyphosate, and on occasion, Crossbow mixed with glyphosate.

There is mechanical means of control. Having a good idea of the root depth of my infestation, I started at the perimeter, and using my loader mounted forks, I used them as spears. I make sure I am at least a couple of feet away from the crown of the plant. I pry up, and take a large chunk of soil, (mine is heavy clay), and flip it onto the ground.
Once you've done this, it is very important to heavily sow some deep diving cover crops, and some grasses. This will help choke out the offending thistle.
Then I carefully extract every single piece of root I can find. This forks have proven to be a tremendous tool in my fight against this horrible plant.

I have also gained the victory of a 5 acre infestation of yellow star thistle, and smaller outbreaks, but even worse, of the dreaded goat heads.

When it comes to noxious weeds, my motto: When you think you've gotten them all, think again. You must be in relentless pursuit it you want to maintain the value of your property.

 

[dcyrilc]

I'm glad the only thistle I have to deal with is Bull Thistle. As long as I cut it and don't let it go to seed, I don't have much problem. When I get complacent, it starts to get heavy again. The one worrying me now is that for the last couple of years I've begun to see Tanzy showing up.

 

[forester2]

If you are talking treating hawthorne the tree, you can do a basal spray of Garlon in a 10% solution with a oil based carrier (such as deisel fuel) or a stump treatment of straight glysophate (41%) will kill root system and inhibite sprouting.

 

[jlrsn]

I'm located right against the border of Central CO and NM up at 8,000' in the San Juan Mountains and Ive tried everything over the years. Right now I still have from 2 to 4 feet of snow and anywhere from 2 to 3 months yet to come but when the snow is gone I'm determined to control it! It has thrived when sprayed with an herbicide, when I cut it to ground level I get many more popping up, when I individually cut it below ground level I get 2 or 3 coming up from the root like graphs, and the only way I'm slowing it down is by putting heavy gloves on and pulling the plant, roots and all, when the ground is wet but it takes weeks but little by little I'll control it. I have not let it go to seed for the last 3 years but.........
Good luck,
Jim

 

[gdh]

How about Round-up? Is it effective just to spot spray Round-up on the canada thistle?

 

[AchingBack]

How about Round-up? Is it effective just to spot spray Round-up on the canada thistle?

Yes, Round-up/glyphosate is effective. I found plant that had reached about
18". My sprayer was empty so I decide to make a normal strength solution, and poured it into an old tray. I bent the plant over into the tray, put a rock on it, and watched it succumb over the next few day. I figured the continual supply of herbicide would get down deep into the system.

I've also used a paint brush to apply weed killer to the terminal buds of the plant. You don't necessarily have to coat the entire plant. It depends upon whether or not the plant is in an active growth stage. If it isn't, kill time and success are hampered.

 

[Iplayfarmer]

I'm glad to see this thread. I've been fighting thistle for a few years now. The thistles and I are at a stalemate.

The best thing for the place so far has been good grazing practices with sheep, and multiple mowings throughout the season. I was told that curtail would be my best weapon, but I haven't tried it yet. I'm still working on getting a sprayer. Rumor has it you have to kill a thistle three times before it's dead.

 

[radman1]

How about Round-up? Is it effective just to spot spray Round-up on the canada thistle?

I would not use round-up because you will kill everything next to the thistle as well and leave a dead spot which will invite other weeds or more thistles. Any drifting of spray will kill stuff in the path. Also round-up costs much more and IMHO there are better and cheaper sprays for that task. I spray canadian thistle and use 2-4-D in a fairly strong mix. A good stand of grass to compete with the thistle is probably the best way to compete for the long term. Don't overgraze or mow to much.

 

[jda1961]

you have to kill the roots to kill the thistle, you can cut it as low as you can but if the roots are entact it will just come back, spraying is the way to go with thistles, stick weeds, wild rose bushes too.