Controlling Canadian thistles

I have a one acre windbreak in CRP that has a few patches of Canadian thistles that I would like to get rid of. In my other CRP land I got rid of the thistles by mowing them in August and then fall spraying the re growth with Grazon.

I would like to use Grazon in this windbreak but it has a row of American Cranberry bushes that have finally caught hold and are growing like crazy. The next row is oak trees. I'm afraid of the fumes from the Grazon killing the cranberries and possibly hurting the oak trees. After all the work and TLC I have put into this project I'm very cautious about using any kind of spray anywhere near to those cranberries.

Any suggestions on what to do? Is there some kind of a selective systemic herbicide out there that will not fume up and drift to other sensitive plants?

Perhaps a rope-wick applicator and Roundup would work for you. The best time for that (or spraying) is into August when the thistles are forming buds.

If it's only an acre, wait until they are about to bloom then hack them down at the surface with a machete or sickle. I've had good results spot spraying with 2,4D and round-
up if you wanted to spray.

Use the Weather feature of your PC or smart phone. Or just hang a 3 foot ribbon from one of the trees, Spray when the wind is taking all the drift away.

When I was a kid my Dad used to send me out with a sack and old pair of scissors cut heads off don't come in till milking time!

I have used a product called thistle down, It comes in a 8oz bottle that costs about $36. you mix it at a rate of about 1/6 oz per gallon and apply sparingly to the weeds, takes two to three weeks to see results but it will kill them. it can be used around other plants without damage.

DO NOT USE Grazon around any bushes or trees that you want to keep. It contains the same ingredient as Tordon and it will kill your bushes and many trees.

I have used Clopyralid sold as: Stinger�, Reclaim�, Transline�. Confront, Curtail, Millenium Ultra . It is not cheap (around $80 per quart) but will get the thisltes. It is labeled to be used in cranberries.

Here is a link to the full label on Stinger:
Dows Stinger label

Stinger is registered on cranberries...that doesn't mean it won't toast them...may not kill them out right but it will knock them back hard if you spray while they are actively growing- until November- March.

You could do as suggested below and make a boom and wipe the tall thistles with 24D / roundup and even stinger. This way there is no chance of hitting the plants you don't want to hurt with drift. They make a "hockey stick" called the Red Weeder...google it. We use them to wipe our cranberries. An acre really wont take that long to do, infact its good to wipe a couple times as you will miss some.

Grant

LONTREL is the product to use.........it is deadly on thistles but will not harm any woody species, other than those in the locust family. It is not cheap but it is more effective in killing thistles than Round-up. I often add 1 oz/A when spraying corn if Canada thistle or sow thistle is present. Will completely kill the plant, not just the top growth.

Best way to control any Canadian , Just give them plenty of American beer, EH !

We've been fighting thistles for the last 3 years in my MIL's pastures. First year we cut the blossoms off since we discovered them too late
in the summer then sprayed them. If you just cut the plant off at the bottom it will put any and all of its energy it has left into the
bloosom to form any seeds it can. That's any plants' job is to reproduce. We found out the 2nd year of spraying is to spray early. We started
in May and got them when they were young. They're easier to kill then. That has really helped in controlling them. We just used brush killer
but we didn't have to worry about other plants.

Canadian thistles can be controlled by mowing. If they are not allowed to head out, they will be dead the 3rd year. Or do as others have said and buy the correct chemicals

I have been using Milestone here for about 6 years,, getting the best results I have got in the last 40 years,, if used right it will not kill grasses, I have not heard of some of the others posted here,, some sound good as well, our County pays for 80% of chemical for Noxious weeds this helps a lot with the cost for us here
cnt

I don't know much about it, but after I left the ranch they got some kind of bugs which eat the seeds out of the flowers. As near as I know, it worked.

Do like our neighbor did back in about 1948. He bought a new Ford 8N - 10 year old son wanted to take it for a drive down the road. Dad said, "keep it in 3rd gear". Son didn't of course - when he got to the corner, he reached for the hand clutch, as all he'd ever driven was a John Deere. Ran into a corner post and did $70 worth of damage (as I remember). Dad had him dig Canadian Thistles at a penny apiece and bring them up to the barnyard for counting each day. You do the math.

Didn't teach the kid a thing - he was always a crazy driver in a few years.

JD I have used Stinger in the past in crop land and it did a good job of killing the thistles but it took two passes a year apart. LONTREL has Clopyralid in it too but I didn't study the label long enough to get the formulation. It took two tries with Grazon to whip the thistles in my CRP filter strips with one year between the first and second application. The label warned against a second application within several years of the first app, I forget how many years, but I did go ahead and respray the second year after the first application and I nailed every single thistle. They were getting thick in some areas so I am very pleased with the results. Because of the Tordon in it I won't be able to crop that land for awhile but that's not a problem.

By judging from the replies here Stinger might be the one to use. I'll Google the label first. I don't have much faith in advice from the local SCS people because they just open a book and repeat what the book tells them. Thanks. Jim

Just keep mowing them.... Seriously. Best thing you can do. A hot dry summer is a real killer on thistles. Mow them flat before they bloom, then all of their energy is expended on regrowth... and as long as they can't set seed they will eventually die after a couple of years.
We killed them dead here in one year... a hot dry summer... nipped them at just the right time and they were gone. That was 10 years ago and they're still gone.

Rod

I certainly could keep mowing too. I would have to pull the thistles the mower cant reach. This is seeded to Timothy/Blue grass. When I enrolled this one acre into CRP I told them I prefer to seed blue grass because it will hopefully be a shaded lawn after the CRP contract retires. I was told I had to seed the timothy along with the blue grass. Last year I let it grow without mowing, it's not supposed to be mowed except for weed control and the Timothy/blue grass grew so thick it smothered out in some small areas this spring. Those small areas now have weeds so it looks like regular mowing is what I will have to do regardless of thistle control.

One thing too. You will need to burn them now just to keep them from going to seed. Then try to hit them as late in the fall as you can. IF you can hit them about a week or two before the first killing frost you will really work on the root system.

Right now the plant is not storing that many nutrients in the roots. It is focusing the energy to the reproductive parts of the plant. Once it blooms and goes to seed then they start to store nutrients in the root system. This is the time to hit them with a systemic herbicide. You will get a much better long term control this way.

Also you will never get full control of Canadian thistles in one year with anything that allows anything else to grow. They are a tough weed to control as they can reproduce form the root system, tuber, and seed. So the second and third year application is usually getting "new" regrowth.

BE glad your trying this now. There are several good herbicides that really work controlling them now. I rented a farm years ago (early 1980s) that the prior owner had allowed them to get totally out of control. There where spots as big as an acre that where solid thistles. I farmed that farm ten crop years. I sprayed them with RR, 2-4d, and several other chemicals of the day. I burnt them, I mowed them, I deep tilled the bad spots. I even pastured some hogs in one bad area to see if they would root out the tubers. When the farm went into the CRP program it still had about half the thistles I had started with. I never did get the one bad spot totally killed off at that time. I took care of it for the owners after they entered it into the CRP program. We just mowed the bad spots so they never got to go to seed. It DID NOT kill them. So the fellows saying three years of mowing will kill them is not right in real bad infestations. We finally got them when Grazon came out. It took 3-4 years of spraying them to get them 90% under control. There still are seeds that come up in different spots on that farm. It is still in the CRP program.

(quoted from post at 03:16:52 07/16/15) Best way to control any Canadian , Just give them plenty of American beer, EH !

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"American beer" - isn't that one of those oxymorons? :lol:

I don't think you can beat a grub hoe, now finding a reliable operator,,,,,,,,,,,,

JD, I like your idea. Mow down now and spray right before first frost, or maybe even right after first frost. Like you say timing is everything. I killed a thick Canadian thistle patch in a corn field with 2-4D-Banvel one time. Neighbor finished up spraying his corn with 2-4D-Banvel back when we used it on small corn. He called and asked me if I had a use for what was left in his sprayer so I took his sprayer and soaked this ultra thick patch of thistles. It was so thick I couldn't see the corn. Every thistle died for good, none came back. The corn in that patch looked spindly and silver for the rest of the season, but I got the thistles.

(quoted from post at 07:46:20 07/16/15)

(quoted from post at 03:16:52 07/16/15) Best way to control any Canadian , Just give them plenty of American beer, EH !

Click to expand...

"American beer" - isn't that one of those oxymorons? :lol:

Click to expand...

I think we ought to build a fence, and have the Canadians pay for it. It would be AWESOME!!! 8)

I'll second Lontrel it is a little pricey but very effective.

(quoted from post at 08:16:52 07/16/15) Best way to control any Canadian , Just give them plenty of American beer, EH !

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That would just ssip this Canuck off.......American beer is like xes on the beach.

Spraying late has the advantage of the cranberries being more dormant then as well. Also you OAK trees will not have green leaves to absorb the chemicals either.