How to get rid of canadian thistle

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In the past I have done all the growing that I could organically--I now have a 10 acre pasture that is thickly infested with canadian thistle. There is way too much to just cut off a few here and there and solve the problem. Others in this area cut the field and then spray for the thistle---would cutting the field and then sowing other grasses to choke it out work--or do I just give in--cut and spray??? What would you do?? Thanks--Lynn

-- Lynn Royal (homesteadmama@aol.com), July 12, 2000

Answers

Hi Lynn. I have battled this miserable but in an odd way sort of pretty weed for 6 years without chemicals and have had some notable success. Starting in real early spring try to overstock your pasture with more than the 10 acres can really carry with a mix of horses ,sheep and cattle if possible. Let them keep it croped like a golf course and they will eat much of it. After the thistles that survive get real big and are in the flowerinf stage ( not setting viable seed yet) mow them buggers down! after mowing , re-stock the pasture and graze it hard till fall. You want to go in to winter with the pasture cropped down to the ground. In late winter to early spring start frost seeding clovers and alfalfa ( depending on where you live) Frost seeding is broadcasting seed on to the surface early on frosty mornings when the sun will warm the surface and melt the frost, causing mud to draw the seed in. Sounds hoaky, but it does work. Another year of heavy grazing ( dont get carried away, your trying to exhaust the root system of the thistle , not the grass and legumes) and dont let the thistle go to seed! wait untill it flowers again and mow it down!I have found that when you wait untill the plant gets real big and is drawing a lot of energy from the sun and you mow it down tight to the ground it really sets the thistle back. Here in Illinois it will try one more time to go to seed before fall but it doesnt get very big. Heavy grazing and diligent mowing, and never let it go to seed. May not be as fast as chemicals, but it will work. We have made a big improvement here following this system. Good luck. Mike

-- Mike (mstydale@aeroinc.net), July 12, 2000.

Hi Lynn. When we moved here 2 years ago, this place was nothing BUT 10 acres of thistle. Lots of people told us it was just too much to tackle. Part of the problem was the fact that the farmers who grew corn here would spray heavily with chemicals and the thistle was the only life form that could survive. And without any competition from other weeds, grasses etc...it thrived! After 1 year of mowing it down repeatedly and spreading grass seed wherever we went (on about 3 to 4 acres)we have won the skirmish but not the battle! We still have 6 acres of pasture full of thistle. I agree with Mike, the cattle idea sounds like alot less work on your part in the long run. We have a lovely grass yard but have made alot of work for ourselves in the process.....Good luck. Judy

-- Judy Bates (trailhppr@msn.com), July 13, 2000.

Ok folks, you are going to have to help me out here. I seem to remember reading an article about someone using, I think, either donkeys or goats for thistle control. Am probably wrong.

-- Ken Scharabok (scharabo@aol.com), July 13, 2000.

Recently on another thread, someone mentioned success with pouring vinegar on the base of thistles. She said it took a few days, but they turned brown and were most unhappy.

-- snoozy (allen@oz.net), July 13, 2000.

I don't think you can. My dad tried for 40 years to get rid of them around our cattle pens and they're still there. We got some hay from Kansas back in the '50s that had them in it and it got started that way.

-- Joe Cole (jcole@apha.com), July 13, 2000.


A philosophy I've heard is that weeds are weeds because they're not stock food. That is, nothing eats them; and they're not evolved to handle being eaten (or mowed). If you've got weeds, and you treat them like lawn - mow them flat consistently, they'll give up and be crowded out by plants that can handle it (i.e. grass, clover, etc.)

It's a lovely theory, and it does work with some weeds - mow, or as above stock heavily. Other weeds, unfortunately, will handle it by adopting a prostrate growth, and possibly spreading by vegetative growth rather than seeds. I'm talking generally here - I don't know the particular weed, or if I do it's by another name.

Most animals won't actually eat thistles if they've got a choice (and that choice can involve a fairly strenuous weight-reduction diet), but goats and, I understand, donkeys, will eat thistle flowers. They reach in between the prickles and delicately pick the flowers - nearly as good in the long run.

The other time-tested method of weed-control involves a different biological agent - you and a hoe. From early in the season, divide the pasture into small blocks, and work over a block a day, chipping weeds with a hoe. If you're feeling really good, do a second block. You can get a surprising amount of small pastures done, a little bit each day, if you keep at it. This is what you ought to do anyway, pasture and fence-rows, after whatever method of controlling them has had effect, simply to stop them from coming back.

-- Don Armstrong (darmst@yahoo.com.au), July 14, 2000.


Lynn, I don't have the thistle problem you do, but I tried vinegar after someone posted about it. It WORKED. Well over 90% kill rate, most of those that were still partly alive got a second spraying and went bye-bye. Easy to do since you can do it in any wind conditions, you don't have to be dressed appropriately for spraying, kids, dogs, cats, bottle lambs, everybody can come along to help and the worst that will happen is that they'll smell like pickles if they get sprayed.

The most important thing you can do right now is to keep them from going to seed and spreading. My sheep eat most of the flower buds out as a special treat. If you can mow, or otherwise cut the plants, do it. While the thistles will still spread from their roots, stopping seed production has to be your first goal. Makes the neighbors a bit happier too. I don't know what stage your thistles are in, but if they've got more than a tiny tight flower bud, collect and burn the plants (collect and burn all of them if you can, the only thing more miserable to tangle with than a live thistle is a dead thistle, and the dead ones will harm any grazing stock). If you spray with vinegar, or with an herbicide, fresh cuts will help get the poison into the plant and greatly increase the kill rate.

There isn't anything that I know of and that you would want, that can out compete thistles. You've got to slow them down first. Somewhere I once read that finches don't nest until they have thistle down for their nests. They also love the seeds. So the is a small upside to thistles. Gerbil

-- Gerbil (ima_gerbil@hotmail.com), July 14, 2000.


Ken, You probably read about using Boer goats to control thistle. I read an article too about it and in some areas of they are turning out huge herds goats and having success at it. Wish I could remember where I read the article at though.

We have thistle as well and just go out and cut by hand. Unfortunately, we have a neighbor that doesn't control thiers and the seed comes to our property every year. Our Nubian goats don't like thistle, so they are no help at all.

-- beckie (sunshine_horses@yahoo.com), July 17, 2000.


We have a terrible infestation of Canadian thistle in our new windbreak and are desperately trying to get rid of it without harming our little trees. Someone suggested using salt on the thistles, but I'm afraid that wouldn't do the trees any good. Will definitely try cropping and vinegaring the nasties and report on any success we have. (Everyone out here just hires a crop-duster to spread poison over the whole area, but that's not an answer for us.)

-- Lynn Walker (lwalker@owlcroft.com), July 06, 2001.

Whoever said, "you and a hoe" is the answer to Canada thistles hasn't met them yet. These thistles have roots that can go down 3 feet or more, and spread laterally 15 feet or more to reproduce new thistles. You might be able to slow them down but you can't stop them with a hoe.

-- joey (jkmalone@uswest.net), July 20, 2001.


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