# Looking for Tenacity/Herbicide pointers



## bensjj91 (Apr 25, 2020)

I have used tenacity blanket applications on 3 separate occasions now, and have been disappointed in the results. Each time it is the same story. I spray tenacity at the rate on the label. I use 2tsp tenacity, 3tsp NIS, and some blue dye across 2000 sqft in a 2 gallon hand sprayer. Its difficult to get an even distribution with a hand sprayer, but I think I am pretty close. The result after about 10 days are weeds with about 30-40% of the leaves pale or bleached and eventually recover. At the same time I have areas of grass that also have some light bleaching. Again, I am working with a hand sprayer so these strips or areas are pretty clearly from light over application. I've never over applied so much that it kills the grass, but it is enough to keep me from making multiple applications. I don't understand my issue. I feel like people express having such success with tenacity.

Most recently I did a lawn renovation, I did not apply tenacity at seeding (in part ran out of time and in part because of my experience with tenacity). Now I am dealing with a fair number of weeds such as dandelions, crabgrass, and clover. I seeded with the SS5000 sunny mix and it came in great minus the weeds. I figured I'd try tenacity (6 weeks after germination) and got the same results described above.

Here are my thoughts on what I might be doing wrong:
1) Weeds are too mature and require multiple applications - *but should I still do subsequent apps if I notice light grass bleaching after round #1?*
3) Tenacity is not the best choice for killing mature weeds. At 6 weeks after grass germination, I am considering most weeds mature. Crabgrass is probably 3 tiller stage and beyond, etc. With my hand sprayer I just didn't feel confident spraying the new grass sooner.
2) Not getting proper application rate or hand sprayer is not going to cut it for blanket applications. I really do think I am getting pretty close to label distribution though...

In my failures with tenacity, I have gone to "Weed B Gon Plus Crabgrass". I think it works great and have had great success with it. Two thoughts I am looking for input on:

1) I notice when I use this product it sticks evenly to broadleaf weeds, but beads up on weeds such as clover. In turn I notice weeds like clover take several applications to kill off. Yesterday I added some NIS to the mix and it seemed to solve the beading problem, but it also sticks the the grass more too. After reading up a little more, I found an article mentioning the beading up is intentional and part of the mix design to allow physical "selection" of weeds vs grass. Guess I am going to find out is that is true... *does anyone use or recommend using NIS with "Weed B Gon Plus Crabgrass"?*
2)I've only ever used "Weed B Gon Plus Crabgrass" for spot treatments. *In the case of my lawn reno where spot application would take forever, any recommendations on herbicides for blanket applications if not tenacity?*

Sorry this was long winded. Thanks in advance for any advice.


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## jha4aamu (Oct 16, 2017)

I think your biggest issue was expectations. Tenacity just isn't a good weed killer in general. So its really not applicable for blanket apps. Conversely, Tenacity is the preferred herbicide at seed down because it does have some pre-em qualities that will suppress weeds for a few weeks while the new grass has a chance to establish.

For your clover, WBG CCO (with triclopyr) is going to be what you need to knock that out.

Ive also never heard of the "beading" being an intentional part of the selection process btw weed and grass for a herbicide. The NIS will decrease the surface tension of the herbicide and allow it to coat the entire leaf of the weed for more contact and better absorbtion (and better kill). Atleast that is my understanding of it.


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## bensjj91 (Apr 25, 2020)

jha4aamu said:


> I think your biggest issue was expectations. Tenacity just isn't a good weed killer in general.


I was wondering if this was the case. I wanted to tread carefully before I made any accusations about the effectiveness of tenacity as a post-emergent.

Also, to clarify, the article I referred to was not actually an "article". It was a post from a user and the statement was not supported in any way. So I am not vouching for the bit about "beading as an intentional mode of selection" -though it does seem to make some sense.


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## Harts (May 14, 2018)

2021 is the year of Tenacity misuse. Part of growing in this hobby is learning and you've learned a valuable lesson - don't use Tenacity as a general weed herbicide.

The best weed killer is a 4 way mix of Triclopyr (WBG CCO) mixed with 2,4D, Dicamba and Mecoprop (regular WBG or Killex).

You'll need quinclorac for crabgrass but a pre emergent app in the Spring will be your best bet.


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## jha4aamu (Oct 16, 2017)

bensjj91 said:


> jha4aamu said:
> 
> 
> > I think your biggest issue was expectations. Tenacity just isn't a good weed killer in general.
> ...


Water beading is a result of its surface tension and the addition of the surfactant reduces that surface tension. Perhaps weeds have a waxier leaf surface than grasses (ive never heard that however)


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## PerennialRyeglass (Sep 9, 2021)

Harts said:


> 2021 is the year of Tenacity misuse. Part of growing in this hobby is learning and you've learned a valuable lesson - don't use Tenacity as a general weed herbicide.
> 
> The best weed killer is a 4 way mix of Triclopyr (WBG CCO) mixed with 2,4D, Dicamba and Mecoprop (regular WBG or Killex).
> 
> You'll need quinclorac for crabgrass but a pre emergent app in the Spring will be your best bet.


Could tenacity not be used as a spot treatment if there are trees/ornamentals nearby? My understanding is that it's less risky to use tenacity versus chancing dicamba taking out/damaging shallow rooted trees in the adjacent area. Am I way off with that assumption?


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## jha4aamu (Oct 16, 2017)

PerennialRyeglass said:


> Harts said:
> 
> 
> > 2021 is the year of Tenacity misuse. Part of growing in this hobby is learning and you've learned a valuable lesson - don't use Tenacity as a general weed herbicide.
> ...


If your goal is to kill weeds, tenacity is not a great option. Selecting a herbicide thats safe for ornamentals is different than selecting a herbicide that will be effective in knocking out undesirable weeds.


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## ABC123 (Jul 14, 2017)

Keep your pre-m barrier up all year round, including winter. Less and more frequent applications is always preferred. After a reno thats been trough winter shouldnt see much weed pressure. If theres any that show up the next season they wont show up after that if the pre-m barrier is kept. Frequent low N apps and pre-m does wonders.


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## ENVY23 (Sep 14, 2021)

Harts said:


> 2021 is the year of Tenacity misuse


So much truth. I constantly see posts on reddit where people say things like "sprayed some Tenacity on my dandelions today." Not sure why Tenacity recently became some miracle herbicide. It has it's place, but there are cheaper, more effective options out there depending on what you're targeting.


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## Mardel74 (Aug 16, 2020)

Tenacity has lots of marketing from DIYers in YouTube, I'm guilty myself(before I found this great comunityTLF )of doing blanket spray of tenacity and speed zone mix with great results probably it was more killing from the speed zone,but the whitening produce by tenacity make you fill good. I know better now,is a learning process I glad I found this place


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## Harts (May 14, 2018)

PerennialRyeglass said:


> Could tenacity not be used as a spot treatment if there are trees/ornamentals nearby? My understanding is that it's less risky to use tenacity versus chancing dicamba taking out/damaging shallow rooted trees in the adjacent area. Am I way off with that assumption?


In my opinion, the goal in lawn care should always be to use as few chemicals as possible. Getting your lawn to a point where you don't have to use post emergent herbicides should be the goal. Thick healthy grass with properly timed pre-emergent applications, will virtually eliminate the need to spot spray broadleaf weeds.

Until you get to that point however, I would still recommend a herbicide that is right for the job. You wouldn't get very far using a screwdriver in place of a hammer and despite Tenacity potentially being safer, it might also mean repeated applications.

If you have ornamentals you are worried about and you are spot spraying, get yourself a cardboard box to place over the weeds. This will protect your gardens and ornamentals from spray drift. This is what I did when I killed off some patches of clumping fescue a few years ago:


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## bensjj91 (Apr 25, 2020)

Harts said:


> 2021 is the year of Tenacity misuse. Part of growing in this hobby is learning and you've learned a valuable lesson - don't use Tenacity as a general weed herbicide.
> 
> The best weed killer is a 4 way mix of Triclopyr (WBG CCO) mixed with 2,4D, Dicamba and Mecoprop (regular WBG or Killex).
> 
> You'll need quinclorac for crabgrass but a pre emergent app in the Spring will be your best bet.


Harts, thanks for the feedback and I appreciate the patience - as it sounds like this topic has resurfaced commonly. I'll store the tenacity away for my next lawn reno. Now that I have some validation on my observations of tenacity as a post-emergent, I'll have more confidence using it as a pre-emergent.

Can I use the 4 way mix you described as a blanket spray? From what I have read on TLF, it sounds like most are for just grinding it out and spot spraying weeds even if there are a lot. In my case, that is what I'll end up doing. I am still curious though, what mix do people used for blanket sprays of very large lawns with weed pressure?


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## Harts (May 14, 2018)

@bensjj91 yes you can use that 4 way mix as a blanket spray.

You can also look into getting something like SpeedZone which has 2,4D and Triclopyr. This is what I used at my new house. It comes in a 1 gallon jug - I have 38K square feet.

Any common herbicides can be used for spot and blanket spray applications.


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## ENVY23 (Sep 14, 2021)

To eliminate drift for precise spot spraying, I cut the bottom off a 2 liter soda bottle, remove my sprayer nozzle, slide the wand into the top of the bottle and out the cut bottom, then reinstall my nozzle assembly. The nozzle will keep the bottle from falling off, then you can just go around setting the bottle down over the target weeds and spraying them. The herbicide will be contained within the diameter of the soda bottle. It looks pretty goofy, but works well.


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## BigBlue (Aug 27, 2021)

@Harts and @ENVY23 those are simple, low tech and perfect solutions for the containment of spray to a particular spot (box and bottle)! Thanks so much for sharing the tips and tricks!

My second Tenacity application after my overseed lit up what I think is a bunch of Poa Trivialis in my lawn (and boy does the full moon make it glow  ) and I have begun to formulate the plan of attack and these techniques will come in handy (probably too widespread to use the glove in glove method this year).


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## Lawn Whisperer (Feb 15, 2021)

BigBlue said:


> My second Tenacity application after my overseed lit up what I think is a bunch of Poa Trivialis in my lawn…


Tenacity can cause bleaching of good grass also., just make sure that it's poa triv.


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## BigBlue (Aug 27, 2021)

Lawn Whisperer said:


> BigBlue said:
> 
> 
> > My second Tenacity application after my overseed lit up what I think is a bunch of Poa Trivialis in my lawn…
> ...


I have been worried about that very issue. The patches are lime green and grow faster than everything else in the lawn. I may have found two plants attached to a stolon (here's other thread with pics: https://thelawnforum.com/viewtopic.php?f=9&t=33005). Nothing else whitened (except a few obvious broad leaf invaders). I'm struggling to get a 100% confident positive identification.


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