Home Forums Hunting & Shooting Hunter's Campfire What herbicide for killing thistles?

I use one of the mixes based on 2-4-D labeled for consumers, basically generic Weed B Gon, at about label rate with good results. Contains Dicamba which I think helps but I don't know that. I expect to use two applications so I'm happy when the first one does it.

If I'm into nuking the area generic Weed B Gon tank mixed with glyphosate at the higher rate gets about everything.

IIRC Crossbow is 2-4D

Nope -

Crossbow is Metsulfuron Methyl - 200 g/L
Picloram - 240 g/L

Myron

We used to mix crop oil with the 24D to get it to work better on thistles. It was off label; maybe there's one that's made for it now. If you're running pasture, put the salt block in anything you want to kill. It works on small patches of tough weeds and the grass usually comes back.

Spot spray those puppies with Milestone. Expensive but vicious. Only takes 4 CC to a gallon. Pffft.
If you can zap it before the flower goes white and pops, you're much better off.
The best part about Milestone is, it's a slow, lingering death. I mean, the plants are dead, but they keel over slowly. Heh heh heh.

Thistrol herbicide may work, but not sure if it is labeled for your application. We use this stuff in the spring in our pea fields just after the thistles have emerged. It does the trick but may be hard to get your hands on without an applicators license.

It is a chemical specific to killing thistles, but carries the "Danger" designation on the label. That is the highest toxicity level for chemicals. As always, follow the label. Below is the label for peas, you may have to search for other applications. It can be used in pasture environments in other countries, not sure about the US.

http://www.cdms.net/LDat/ld2D1000.pdf

http://www.pesticideinfo.org/Detail_Product.jsp?REG_NR=07136800005&DIST_NR=071368

IIRC 2-4-D for home use is about 7%,(Ortho from Home Depto etc.) for farmers is 48%. Use the 48% with oz of Dawn to each gallon.

Pulling these numbers from memory from several years ago so check the labels.

I have been mixing the stronger 48% at 3 oz to the gallon of water with dish soap. Not 100% sure on you thistle fight.

Where did you find that info?

When I search Crossbow,Dow lists the ingredients as Triclopyr and 2-4D

Milestone works great! Yes, it is more expensive initially, but when you consider how little you have to use, it's a bargain. You can mix it with your 2,4,D. READ THE DIRECTIONS so you don't get hurt.

Get some marker dye from the store to put in your concoction. It will show you where you missed.

Also, I've found that a bit of Dawn dish soap helps break down the defenses of the thistle.

If you don't get spray on the ENTIRE plant, it will somehow survive enough to go to seed. Just getting the base of the thing won't be enough.

The thistle is a biennial. This means it grows the first year and seeds the second. If you can get all the little ones you can, it will make a huge dent for next year.

Lastly, spot spray in the fall as often as the weather permits.

I had a huge problem with thistle last year. Some of them were over six feet tall. This year I have less than 10% of what was there last year.

Good Luck!

Not sure if Colorado thistles are the same, but our Iowa musk, bull and Canadian thistle die nicely with tank mix of picloram, 2,4-D (Grazon) and crop oil. The best time is to get them early, just a whif will kill them when they are in the rosette stage. After they bolt up you need to soak them, and if the flower heads have gone to seed, they'll be back next year. They seem to come up for 2 years from a ripe seed head. I pluck the seed heads off musk thistle if I miss them, but that's not practical with Canadians. I try to go back weekly if I can to catch any stragglers that come on later. Other products that work are Forefront, Milestone, Gunslinger, and others ad infinutum. Ask at your local farmer's co-op what they recommend, or at the extension office.

I use a 15 gallon spot sprayer with a 12 volt pump. Works good from the pickup or ATV if you can get there. Not sure how to set it up on a pack saddle?

Canada thistle won't tolerate repeated cutting either. Here in Pa. cutting alfalfa at least 4 times a year will kill the thistle growing in the alfalfa. Not sure that applies in your situation right now but something to keep in mind.

I liked a tank mix of 2-4,D and Banvel but you need to get them before they bloom. And rosette stage is even better.

Dale

Mossy,

The product label I looked at was one I downloaded directly from Dow probably 5 years ago.
Just looked again, and the label was for a product called "Crossbow One Shot" Guess it isn't the same thing.
I stand corrected for wrong information.

Myron

If you're cutting the blossoms off, take a squirt bottle of Roundup and squirt it right down the hollow stalk.
Other than that the only thing that'll reliably take out Canadian and Musk thistle is tordon. You need an applicators license for it, and like 2 4 D you need to be very carful about how much you apply to a spot as it will take everything out, and can and will leach out thru the roots and hit trees and shrubs.

Milestone

Ranch,
I hate to be a smartass, but I don't think with 20 acres he is going to be cutting the blossoms off where he can take a squirt bottle and spray down individual stalks!

Myron

Myron go back and read slowly so you don't get confused.
You'll soon see a couple of things.
1. Where he's talking about is not his private land, and as you may or may not know, apply any chemical to land that don't belong to you can/will get you into some hot water with the feds..
2. As he says he " ride thru about very third day and take a big knife, get off and cut the big ones" a little squirt bottle of round up and a couple of squirts down the hollow in the stalk, and,,,,, well if you've ever done it you know what'll be the result..
Plus it might not cause a big enough die off that some goody two shoe nature lover won't go screaming to the local authorities about what's killing all those pretty blossoms in the creek bottom.

Roundup does work; you can paint it on or spray very carefully (no wind) to minimize damage to other plants.

Hate using sprays but we had an infestation of Canadian Thistle that we just couldn't lick... nasty stuff.

My understanding of how Roundup works is that putting a drop down a cut stem is NOT effective, or at least not ideal. It needs to be absorbed throughout the leafs. But I could be wrong, that's just what I'm remembering.

Ranch,

If you want to do that over 20 acres, have fun!

Myron