Canada Thistle - Oofda

How the Heck do you kill canada thistle? I've tried Tordon, Mecamine D, and old mixed 2-stroke gas on these sons-a-guns, and the only thing that touches it is the gas. You have to use a fair amount of it on the weeds though for it to really do it's job. I'd rather not have to continue to use gas on a lawn, but I can't for the life of me kill these stinking weeds They're taking over my backyard, and I'd like to let my young kids run around out there without getting pricked. Any fool-proof methods that won't kill the grass along with the thistle?

The key principle to Canada thistle control is to stress the plant and force it to use stored root nutrients. Canada thistle can recover from almost any stress, including control attempts, because of root nutrient stores. Therefore, returning infested land to a productive state occurs only over time. Success requires a sound management plan implemented over several years. Mow then spray, once it starts coming back up.
Table 1. Herbicide to control Canada thistle in pasures, rangeland, natural and noncrop areas.
Herbicide Rate (Product/A) Application
timing Comments
Tordon 1 quart Anytime when weeds are rapidly growing Fall applications consistent results; may need re-treatment 1 to 2 years
Milestone 5 to 7 fl oz Spring at pre-flower-bud growth stage; or fall Use higher rate for older or dense stands; Milestone may be used to edge of ponds or streams; may need re-treatment 1 to 2 years
Transline 0.67 to 1.33 pints Spring after all shoots have emerged, rosette to early bud growth stages; or fall Apply 1 pint/A or more in fall; may need re-treatment 1 to 3 years
Perspective 5.5 oz Spring rosette to flower bud growth stage; or fall Use with a non-ionic surfactant at 0.25% v/v
Telar 1 oz Spring bolting to bud growth stages; or fall Fall applications most consistent results; essential to use non-ionic surfactant at 0.25% v/v; may need retreatment 1 to 2 years
Banvel,Vanquish, or Clarity
(dicamba)

2 quarts Spring rosette growth stage; or fall Fall applications most consistent results; may need re-treatment 2 to 4 years

Grazon Next kills it you just need to give it a bath, I drive real slow when spraying around it.

Grazon P+D

They brag this up this little bottle the stuff covers several acres.

Crossbow kills it and a lot of other weeds down here.

I use 2-4-D here.

A good sharp hoe

Milestone and crop oil is what I'm spraying on our musk thistles as I speak.

This is what I use. Spring and fall. Might take a couple years to get them under control if you got a bunch.

Another vote for milestone.. Has worked very well for me. It does pretty good on wormwood too.

crossbow or round up -- round up is batter on canadians -- haven't tried the vastland ( tri chlor) on them yet.

doubt there's anything better i use the 65% active ingredient spray when they're small and check your neighbors yard to see if thats where they came from

Milestone and a surfactant. It's all I use and all I need.

We have had good luck with this. Knocks it down much more reliably then 2-4d.

Thistle needs a surfactant. 2-4d, crossbow, redeem, curtail with glyphosate, all will knock it down. Best if you can catch it when it's 8" tall or less.

Another vote for milestone

X2.

Canada Thistle spreads on rhizomes so wouldn't recommend the hoe method. You just turn one plant into 5. Grazon next does a pretty decent job. Spray prebloom or fall 4-6 weeks prior to frost

I let it get to about 5 ft tall, then I snip it off just above the ground and coat the stump with 20-30% glyphosate.

You guys talking about 5 foot Canada Thistle ive never seen it grow that tall. Our Canada Thistle grows about waist high at best. Canada Thistle forms dense patches that eventually take over areas of the field. We do have tall thistles like musk, bull and ploomless thistle those are entirely different creatures to control then Canada Thistle. Canada Thistle is also a perennial where the others have biannual grow habits. Canada Thistle is a nightmare for most people.

2-4d works well if sprayed early in the rosette stage. You must not have used a surfactant with your tordon. Straight tordon 22k will kill most any broadleaf and mature trees and fish.

At least sharp hoes don't kill fish, unless you are a caveman.

Liberty (Glufosinate) will kill it

Years ago they dug the roots out that sounds like some hard caveman type of work.

A pint, a pound, and a pinch!!
Pint of 2-4-D
A pound of Atrazine
A pinch of (Ally) 1/16 of a oz/ac
Add pint of Dicamba too

Nice comeback.

1/2pint,2/4D, Quart of diesel fuel, couple squirts dawn soap, gallon water. coat after dew is off.

As many know, I have a certified organic farm and canadian thistle is one of my worst nightmares. Hoes are no good against them as all the plants you see are interconnected below ground. When they are in my perennials I sometimes will wait until they are almost flowering and after a good watering pull them out. I will get about 10" or more of tap root Which just slows them down a little. They'll be back.

My best strategy has been to use heavy duty weed barrier fabric. We also plant heavy cover/smother crops in rotation to try to control.

IN closing, I have been on the same piece of ground all 64 years of my life and still am fighting the same thistle plants that I inherited from my dad who retired in 1976.

We do have organic contact herbicides based on fatty acids. They do a top burn but are no better than hoeing as the tap root will send up another 2-3 shoots immediately.

Thanks for sharing.

Milestone and Surfactant. The Surfactant is a must or your wasting your money.