Knapweed... What is working?

[atlas]

Yesterday I was out checking out a spot before archery opens up. A lot of this area has knapweed here and there but once you get into parts of this burn the knapweed is everywhere, extending a few hundred yards on either side of the road.

I know there are a few species of biocontrol insects but it looks like areas like this are headed for a steady increase in knapweed. What is working and what can be done?

 

[Jamen]

Yesterday I was out checking out a spot before archery opens up. A lot of this area has knapweed here and there but once you get into parts of this burn the knapweed is everywhere, extending a few hundred yards on either side of the road.

I know there are a few species of biocontrol insects but it looks like areas like this are headed for a steady increase in knapweed. What is working and what can be done?
View attachment 236644View attachment 236642

We deal with knapweed up here but not to the extend as other western places. I have been apart of some biocontrol trials. They are pretty slow moving to try and get a population big enough to impact large infestations. Not saying in other parts of the country they dont work better but here it was so so. What i use to spray it is Milestone at 7 ounces/acre rate. Corteva has come out with a new product DuraCor that is the same thing as milestone but with one more active ingredient that acts like a 2 -4D Rinskor is the name of it. The rate i would use is 20 ounces per acre of Duracor that will give you the same 7 ounce rate of milestone. We have seen great results with it. And having a milestone product you should expect to see 2-4 years residual. Ive seen it knock out thistles for 5 years.

Hope this helps.

 

[TheTone]

My opinion, nothing is working and the battle is basically lost. I had to laugh that I saw a FS sign Saturday warning people that spot spraying would be occurring over a three month period along a trail system, meanwhile the knapweed growing within feet of the sign seemed healthy and happy. Prepare for killing the next new invader but finding agencies that move fast enough to do that seems improbable. I basically never saw skeleton weed in areas I elk hunt 10 years ago; now it’s somewhat common and I’ve yet to see any crew spraying it.

 

[YukonGold]

Yesterday I was out checking out a spot before archery opens up. A lot of this area has knapweed here and there but once you get into parts of this burn the knapweed is everywhere, extending a few hundred yards on either side of the road.

I know there are a few species of biocontrol insects but it looks like areas like this are headed for a steady increase in knapweed. What is working and what can be done?
View attachment 236644View attachment 236642

Kinda looks like the BPA line there east of Missoula.

This year seems to have been particularly bad for knapweed in Montana. I notice it wherever I go, but this year I really noticed it.

Agree that the tools we currently have don't seem to be putting a dent. Don't think much can be done until we find a new, more effective biocontrol.

 

[Jamen]

Since we do not have a very large infestation here we sprayed the entire area even if we didn't see any weeds present. I wanted to be sure if seeds moved we would have a herbicide down on the ground already. Seemed to work here. last 2 years we haven't found a plant. Where i worked previously there was a large pasture/ gravel pit that was completely covered in it. Took a few years but we reduced it to a very manageable amount of plants.

 

[Sytes]

Fire and brimstone shortly after spring thaws away the white crap.

Outside from that, spring - I've torched and the next spring our main "city" hub had a semi free/rental for spraying. We finally had our rear couple acres clear of knapweed though knapweed is not a one and done fix.

 

[Straight Arrow]

I have been attempting to eradicate spotted knapweed for many years along the road and near the Gallatin River on our place. Near the river I have mostly dug the roots up (only way to kill it) and along the roads have sprayed Milestone. Occasionally I can catch the county weed sprayer crew and persuade them to spray the roadside and behind the school.
Unfortunately it has spread to so many private properties that it's impossible to eradicate. All that can be done is to treat specific locales which you may be able to access.

Up in the mountains near our cabin, I first dug it out but now have to spray since the patches are getting so large. About all you can do is keep after it in attempting to limit it's spread as much as possible. It is a terrible scourge!

 

[BenInMT]

It seems really bad this year maybe from all the spring rain. Everywhere I’ve scouted is a sea of it.

 

[Carnage2011]

Knapweed is pretty simple to control if it’s accessible. Typically it gets out of hand when there isn’t a large enough budget to spray it all or it’s in Rocky country. 7oz milestone, 1 qt 2,4-d, and a good surfactant will clean it up. Spot spraying is almost worthless for Knapweed as the seeds can sit in the ground for so long that it just comes back year after year if you only spray the plant. If you want control you need to broadcast spray.

Edited to add: Yes, it’s a great year for weeds. The wet spring has made them explode in some areas.

 

[BigHornRam]

After a disturbance like fire it is important to reseed the areas with native grasses to keep prolific non native invasives like knapweed and cheat grass from taking over. Too late for this on this site. The bio control insects do a good job controlling moderate knapweed infestations, but won't make a difference here. Knapweed is a terrible scourge to our western habitat that is only getting worse, not better.

 

[Jamen]

Knapweed is pretty simple to control if it’s accessible. Typically it gets out of hand when there isn’t a large enough budget to spray it all or it’s in Rocky country. 7oz milestone, 1 qt 2,4-d, and a good surfactant will clean it up. Spot spraying is almost worthless for Knapweed as the seeds can sit in the ground for so long that it just comes back year after year if you only spray the plant. If you want control you need to broadcast spray.

Edited to add: Yes, it’s a great year for weeds. The wet spring has made them explode in some areas.

100% agree ive used that chemical combo with very good success. As you mentioned you need to broadcast spray and a lot of times agencies will not do that which is sad. We will do broadcast spray as preventative measures and I've seen very good success. Where i see people fail is cutting rate and not covering a big enough area.

 

[atlas]

Ah, I wish the FS had taken more preventative steps here. It's also an area weeds crew could probably take a truck, certainly an ATV. But the longer it goes I'm sure that will become less likely.

It's cool that people are having good success on private land, which makes sense that people give more attention to their own property.

Too bad we can't do better on public.

 

[D705]

Opensight by corteva is alsoa great option. Very low usage rate 1.5-3 Oz pr acre. Will take it out for couple of years.

 

[Carnage2011]

Ah, I wish the FS had taken more preventative steps here. It's also an area weeds crew could probably take a truck, certainly an ATV. But the longer it goes I'm sure that will become less likely.

It's cool that people are having good success on private land, which makes sense that people give more attention to their own property.

Too bad we can't do better on public.

There are some good projects that take place on public land. Generally speaking the Forest Service is terrible at managing weeds (and everything else for that manner). Montana FWP and the BLM do some good work. RMEF and the Mule Deer Foundation have donated a fair amount of money towards weed spraying and habitat projects.

 

[OriginalOscar]

Study from WY 2017. Anyone know the results?

Wyoming Game and Fish Department - Study on goat grazing to control Knapweed begins

wgfd.wyo.gov

Yes I'm aware of threat to wild sheep but we need to do something.

 

[Jamen]

Opensight by corteva is alsoa great option. Very low usage rate 1.5-3 Oz pr acre. Will take it out for couple of years.

I love opensight! my only caution would be to not use it around desirable trees. The escort that is in there will kill or damage trees and other woody plants. Opensight along with 16OZ of a 2-4D will smoke out buck brush if hit early in the growing season. We have seen great results with that for brush control along with hounds tongue. "Milestone, Opensight, Duracor, Terravue, and now HighNoon" all have the same base active ingredient aminopyralid which is milestone. The products are semi costly but like others have mentioned you will see results.

 

[atlas]

Study from WY 2017. Anyone know the results?

Wyoming Game and Fish Department - Study on goat grazing to control Knapweed begins

wgfd.wyo.gov

Yes I'm aware of threat to wild sheep but we need to do something.

http://www.msuinvasiveplants.org/documents/publications/extension_publications/Montana knapweeds.pdf This was pretty informative. There is a brief section on the success of sheep grazing with herbicide on page 13.

 

[BigHornRam]

City of Missoula brought back domestic sheep after a 5 year hiatus to manage their weed problem.

Hundreds of sheep at work tackling noxious weeds in Missoula

Managing invasive weeds on the hills surrounding Missoula is an enormous task which is why the city has hired more than 800 employees to fix the problem.

www.kpax.com

 

[Oak]

City of Missoula brought back domestic sheep after a 5 year hiatus to manage their weed problem.

Hundreds of sheep at work tackling noxious weeds in Missoula

Managing invasive weeds on the hills surrounding Missoula is an enormous task which is why the city has hired more than 800 employees to fix the problem.

www.kpax.com

FWP had to euthanize 5 bighorns in the past that contacted the weed control domestic sheep on Jumbo.

 

[BigHornRam]

FWP had to euthanize 5 bighorns in the past that contacted the weed control domestic sheep on Jumbo.

Yep. But its city owned land,the residents of Missoula strongly support it, and are paying Helle good money to graze it.