# Bentgrass... tenacity vs roundup?



## sheepfescue (Jul 29, 2019)

Considering factors like time, money, frustration, ease of application, speed of results, and success...

How would you compare tenacity to roundup for bent grass removal, if there is a lot of bentgrass and the bentgrass is mostly in patches on its own?

(A side point): I just sprayed a bunch of crabgrass destroyer (topramezone, similar to mesotrione, which is tenacity), and unintentionally there are giant white patches all over the place.

Although I didn't intentionally target bent grass with the topramezone, it has me looking at the white patches and thinking "why not just hit it with glyphosate, get fast results, rake out and plant new grass?

I understand roundup spraying has to be very very precise and will totally kill what it touches. But I feel like it might be faster, and ultimately more successful?

Just wondering if there are opinions out there on this topic.


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## MassHole (Jun 27, 2018)

Round Up didn't work for me. I had it dug out 6", sprayed, and the dirt replaced. It came back.

If you have huge patches, you should do both (Tenacity / Triclopyr 2 apps in early August AND Round Up 2 apps) and reseed in the fall.


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## g-man (Jun 15, 2017)

Pylex for crabgrass? It is unlikely you have crabgrass in zone 6.


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## sheepfescue (Jul 29, 2019)

g-man said:


> Pylex for crabgrass? It is unlikely you have crabgrass in zone 6.


Roundup's "Crabgrass Destroyer" has tapramezone as the active ingredient.

I do think I have immature bunches of crabgrass, which is why I used the product (as well as the fact the active ingredient is effective against other weeds as well).

I have a plant ID app on my smartphone that said the things I think are crabgrass are crabgrass. But maybe it's not crabgrass.

But in any case it did turn bentgrass as white as glaciers in the Alps... and do that's just what got me thinking about the topic of my opening post.

http://www.roundup.com/en-us/products/lawn-weeds-bugs/roundup-lawns-crabgrass-destroyer1


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## g-man (Jun 15, 2017)

oh wow! Pylex in a ready to use product. I think this is a really bad strategy from the Round Up company. You can see in the reviews that people are not happy with it.

Pylex is similar to Tenacity in the MOA, so it is a slow kill. This is a good product for treating bermuda and other weeds, but for crabgrass, quinclorar is faster, effective and less risk of killing your lawn.

They are only selling the product already mixed and ready to use, so the concentration is low.

Post a picture of your "crabgrass". I think it will not be crabagrass since it is barely germinating now.


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## sheepfescue (Jul 29, 2019)

Ok g-man, I'll post a pic when I can.

Do you have any thoughts on Tenacity vs glyphosate for bentgrass (time, money, effort spent, and effectiveness from point A to point B)?


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## g-man (Jun 15, 2017)

I don't have experience with bentgrass. Tenacity will be the selective approach. All the same rules apply (not dormant, watered) for either approach.


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## uts (Jul 8, 2019)

I would really like this information as well. My backyard has patches both big and small of bentgrass interspersed decent grass and while I think I might go for a total renovation for these areas, saving some of the surrounding areas would be helpful!


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## doogie89 (Apr 29, 2019)

I used Tenacity to kill off bentgrass at my parents house back in 2016. I made a YouTube video of the process. I found that after about 3 years it started to come back since I had used Tenacity. Round Up will definitely kill it off, but not well enough to keep it from coming back. Tenacity will be your best bet. Do 2-3 treatments to fully kill it off then you may have to do an annual treatment going forward to keep it killed off.

https://youtu.be/QjHszetM8Dw


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## uts (Jul 8, 2019)

doogie89 said:


> I used Tenacity to kill off bentgrass at my parents house back in 2016. I made a YouTube video of the process. I found that after about 3 years it started to come back since I had used Tenacity. Round Up will definitely kill it off, but not well enough to keep it from coming back. Tenacity will be your best bet. Do 2-3 treatments to fully kill it off then you may have to do an annual treatment going forward to keep it killed off.


So it sounds like nothing will keep it off .. will tilling help by any chance after tenacity/roundup?


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## doogie89 (Apr 29, 2019)

uts said:


> doogie89 said:
> 
> 
> > I used Tenacity to kill off bentgrass at my parents house back in 2016. I made a YouTube video of the process. I found that after about 3 years it started to come back since I had used Tenacity. Round Up will definitely kill it off, but not well enough to keep it from coming back. Tenacity will be your best bet. Do 2-3 treatments to fully kill it off then you may have to do an annual treatment going forward to keep it killed off.
> ...


My understanding was that the roots to the bentgrass get so deep and intertwined with the good grass roots that Round Up doesn't kill all of them and eventually it will grow again. Tenacity seems to do a better job at getting deeper to kill it off better. The reason for doing an annual treatment going forward would be to keep it in check and ensure you've killed off all the roots. At some point you will have killed them all for the most part. I personally would think tilling would definitely help more than not. The tricky part is making sure you've tilled all the roots, but you can't really see all of them. Beyond that, I'll have to defer to someone who is more of an expert at this than me. I had trouble finding content online about how to use Tenacity to kill off bentgrass a few years ago, which is why I made that video showing my experience.


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## uts (Jul 8, 2019)

^ really appreciate the video, no doubt. And yes, while I wouldn't know where the roots go I realize I will have to kill some surrounding areas as well. My plan was to do an initial blanket application of a big section of my yard, see the bleached area and then do regular spot (if I can call it that) applications. Lol


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## LawnDetail (Apr 15, 2020)

I've had success with bent following these steps. 
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## ryeguy (Sep 28, 2017)

Improve the efficacy of Tenacity for creeping bentgrass control says:

Based on the results of this study, Tenacity should be applied at 1.0 oz. per acre in each of three sequential applications on two-week intervals using a non-ionic surfactant plus UAN with power raking. Power raking will remove debris before each Tenacity application and allow for the greatest control of creeping bentgrass.


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## estcstm3 (Sep 3, 2019)

@ryeguy @LawnDetail Im fighting creeping bentgrass bad, so what would my rate be out of a 2gallon sprayer to cover 8k sq/ft (at least half my yard has this crap mixed in)? how much tenacity, UAN, surfactant per gallon?


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