# Tenacity and prodiamine questions



## Royale_with_cheese (Sep 10, 2019)

Hello, thank you for viewing my thread. So I have quite a few weeds here in my MI lawn, wanting to get rid of them the best I can this fall, and keep them gone. Ive ordered tenacity, however I read that isn't a very effective pre M, so I was considering ordering prodiamine as well. Is this a good route, or am I doing to much too quickly? I'm still very new to this, so any advice I appreciate.


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## Virginiagal (Apr 24, 2017)

It would be helpful if you can identify what weeds you have. Here is some reading material for you on herbicides and there is a link in there to weed ID:
https://thelawnforum.com/viewtopic.php?t=6334

Prodiamine is only a pre-emergent. Applied now it can help prevent winter/spring weeds. You can apply it in early spring to prevent summer weeds like crabgrass. Tenacity is only a short-lived pre-emergent and there are limits on how much you can use it. It is also a post emergent. If you are mainly dealing with broadleaf weeds, it's better to use something like WeedBGon. If you're dealing with violets and clover, the WeedBGon CCO will kill those.


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## Royale_with_cheese (Sep 10, 2019)

I've taken pictures of the weeds, been trying to ID them. If it is mainly broadleaf (which I believe it is, and clovers) why would weed b gon work better? I've read so many raving reviews and results on tenacity? Also yeah I wouldn't use the tenacity as a pre M, that's why I was considering the promiadine as well. Hope I didn't waste money on tenacity, how's the shelf life on it??


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## Virginiagal (Apr 24, 2017)

A discussion of Tenacity, including efficacy on broadleafs:
http://archive.lib.msu.edu/tic/holen/article/2012may14.pdf

Tenacity shines at seeding time as it is one of the few things you can use as a pre-emergent while seeding. Some people use it as a post emergent. Where it is most useful, other than at seeding, is in tackling certain grassy weeds like bentgrass. Ordinary weed killer will kill broadleafs. You already have Tenacity and you can use it if you like. Follow the directions. Prodiamine will be a great help in keeping your lawn weed free.


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## Royale_with_cheese (Sep 10, 2019)

Well I ordered the tenacity from amazon, and it hasn't shipped yet so I can still cancel it. If I cancel it, what weed killer would you recommend? I have a backpack sprayer, so I would like to utilize that. Also do I have to wait a certain amount of time in between applications or weed killer, and the prodiamine?


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## Virginiagal (Apr 24, 2017)

Several weed killers have a combination of 2- 4-D, mecoprop, dicamba (WeedBGon, Bayer, Spectracide, for example) and this looks like a good buy on Amazon:
https://www.amazon.com/Spectracide-Weed-Lawns-Concentrate-HG-96392/dp/B00OHV5S96
They are easy to find at big box stores. You are looking for a concentrate form.

That should take care of most broadleafs. If you still have weeds (like violets) the next one I'd try is a general weed killer that also includes triclopyr (example, WeedBGon CCO).

The concentrates can be mixed and used in your sprayer. Just try the first one and see what's left after that before getting anything else.

Crabgrass will die at frost. Prodiamine in early spring will prevent next year's crop. It should not be a problem to use weed killer and Prodiamine about the same time. Weed killer should be left on the leaves for a certain amount of time. Prodiamine needs to be watered in. So don't use them on the same day, or at least wait to water.


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## Royale_with_cheese (Sep 10, 2019)

Thanks so much for you help, I appreciate it. Looks like the tenacity has already shipped...should I send it back, and order some air8, or stock it in my shed for future use?


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## ScottW (Sep 16, 2019)

Big box store concentrates with triclopyr should take care of most of the broadleaf stuff I see in those pics. Not 100% certain whether that's stilt grass I see in addition to the crabgrass, or if you have different/other grassy weeds.

So you may or may not "need" Tenacity. I keep it around for its utility at seed down and for eliminating certain grassy weeds. I don't know what's its listed shelf life is but my bottle is 5 years old and has been working fine this year. A little goes a long way at 0.5 tsp per gallon per 1000 sqft, tank mixed with a NIS.


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## tgreen (Oct 20, 2018)

Royale_with_cheese said:


>


1)Plantain, 2) clover in the pic but not sure the bigger plant, 3)creeping charlie and 4) dandelion in that order. Not sure on your other ones.

I would not have gone tenacity b/c of the expense but if you have it then look on the label if these weeds are covered. I would have gone with a product like Speedzone, cheaper and probably more effective.

When did you take these pics? These are warm season weeds and you are in MI so a little surprised you are still seeing them but possible. These weeds are about to check out whether you spray them or not. I'd save your money and try controlling these next season.


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## tgreen (Oct 20, 2018)

One more thing. Don't bother with prodiamine now on these weeds. It will not help. These are summer annuals and a preemergent like prodiamine right now does you no good. Run the prodiamine in the spring. Check this u of michigan link below and click on Crabgrass PRE. I don't know your weather but am just guessing you're looking at a prodiamine around early May-ish

http://www.gddtracker.net/


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## Virginiagal (Apr 24, 2017)

If you don't have to seed, you can keep pre-emergent protection on year round. Prodiamine now will protect against such things as chickweed and hensbit which germinate over the winter and early spring.


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## Royale_with_cheese (Sep 10, 2019)

Thanks everybody for your input, I really do appreciate it. Just like with any other hobby there is absolutely a learning curve, and this is no exception. I hear a lot of contradicting advice, or just different I suppose. Prodiamine is fine now, or just as fine in the spring. Pictures of the weeds were taken yesterday (9/20), however it's warm here, 89 today. I just ordered this as suggested by @Virginiagal 

So I think I'll try this, store the tenacity, and use the prodiamine in the springtime.


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## Virginiagal (Apr 24, 2017)

Here's an article from Purdue on why fall is the best time to kill *perennial* weeds, which include plantain, clover, dandelion, violet:
https://www.agry.purdue.edu/turfnew/pubs/ay-9.pdf

You can hold off on pre-emergent until spring if you like but there are no downsides to using it now too. I will never in my lifetime use up my bottle of Prodiamine. I even offered it to neighbors on Nextdoor this year.


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## tgreen (Oct 20, 2018)

Yes, if they are perennial then kill them now. I can ID them but I was wrong on those all being annual. Look them up. Again, if perennial then kill now with your post emergent product.

Running a preemergent now will still not help with warm season weeds. Basically, warm season weeds begin emerging at the first sign of warm weather/ground temps, think spring. Cool season weeds emerge at the first sign of cool weather/falling soil temps in the fall, think late august. If you are looking to use a preemergent then you would want to run it immediately BEFORE the target weed(s) emerge. Your pre-emergent then interferes with root development immediately after germination. Preemergents wear off after a while (look at the label for exact times). If you run a preemergent in September targeting warm season weeds then your preemergent would need to be active from now until June or so. They don't last that long.

If you are looking to control cool season weeds with a pre-emergent, know a couple things: 1) you are too late and 2) most people don't run pre-emergents in the fall for a number of reasons.

Good luck.


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## Methodical (May 3, 2018)

I'm a Speedzone fan with its 4 way threat for post emergent weed kill. I have had great success with it. I also like that it works in cooler temps much better than many other herbicides. I used it this past spring when temps were still pretty cool with success for creeping charlies, henbit and those violet weeds - wiped them right out. I've found it to be much cheaper per application when compared to the Weed B gone and other big box store herbicides. The percentage of ingredients is much higher than those products and therefore you don't need as many applications.

I used Prodiamine for the first time on Saturday and looking to see how it works for those cool season weeds I've gotten in the past, but mostly to ward off poa annua.

The only reason I can see not to use Prodiamine if you plan to seed, so unless you plan to seed, I say put down some Prodiamine now.


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## Virginiagal (Apr 24, 2017)

@tgreen I don't understand why you are so opposed to using pre-emergent in the fall. It is possible to use it now using a dose that will last through February, then use it in March with a dose to last through July or August. You are not limited to one application a year. I'll agree with you that late August would be a better time to use it for the winter/spring weeds. However, not everything germinates, boom, at one time. He can prevent all the weeds that would be germinating the rest of the fall into the winter. The only reason not to use it would be if seeding is planned in the upcoming months.


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## Royale_with_cheese (Sep 10, 2019)

So I bought this concentrate 


However I don't think this will help eliminate the ground ivy. Should I buy some triclopyr and mix it in (can I even do that?)


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## Virginiagal (Apr 24, 2017)

The weed killer that contains triclopyr is inexpensive and you can buy a small bottle of it in any garden center. WeedBGon CCO is an example. I would not mix them. Use one (the general weedkilker), wait a few weeks, use the other.


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## NJ-lawn (Jun 25, 2018)

Virginiagal said:


> The weed killer that contains triclopyr is inexpensive and you can buy a small bottle of it in any garden center. WeedBGon CCO is an example. I would not mix them. Use one (the general weedkilker), wait a few weeks, use the other.


Is there a reason you can't mix them?


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## Virginiagal (Apr 24, 2017)

@NJ-lawn The manufacturers determine safe dosages of the chemicals for an application. Why mess with that? Maybe it would be safe to mix them, maybe not. Any herbicide use is somewhat stressful for the grass so it is best to be conservative in their use. Anyway if you use one and wait for it to take effect you can then see in a few weeks what is left to be dealt with. Then you can target just those remaining weeds without having it spray everything.


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## Royale_with_cheese (Sep 10, 2019)

I've stumbled upon a few threads, members talking about mixing multiple different herbicides. @Virginiagal you've never tried it? Maybe someone will chime in that has done so.


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## g-man (Jun 15, 2017)

@Royale_with_cheese it is possible to mix, but the risk of damage to your good grass goes up. Virginiagal advise is sound. Use the normal 3 way to get rid of 90% of all the weeds you have. Then use the triclopyr for the rest and maybe you can do a spot/some areas treatments.


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## Virginiagal (Apr 24, 2017)

@Royale_with_cheese To answer your question, I have never mixed herbicides. For that matter, it has been years since I used these weed killers because I use Prodiamine and have very few weeds. You can always read the labels of products to see what they say about mixing with other products. You can also call customer service for the manufacturer and ask. I don't think it wise to experiment on your grass.


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## Royale_with_cheese (Sep 10, 2019)

@g-man @Virginiagal I think you're both right, I'm not experienced enough to be mixing chemicals, or my grass probably is t healthy enough to take very harsh beatings. Now my question is should I use that spectracide weed stop, then afterwards use just triclopyr, or would it make more sense to use something like Crossbow that has 2,4D and triclopyr right in it?


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## Virginiagal (Apr 24, 2017)

This is the product to get:
https://www.amazon.com/Ortho-Chickweed-Clover-Concentrate-16-Ounce/dp/B00F4JS3SS
You need only a small bottle of concentrate.

Use the general weedkilker you already have. Wait for weeds to die. Use this next, just on the weeds the first weedkilker didn't get.


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## Royale_with_cheese (Sep 10, 2019)

Okay so quick update, I used the spectracide about a week ago. Haven't seen a whole lot of results yet, however I know it's not going to happen overnight. My question is do I wait about a month then use the spectracide again? Or should I switch to the ortho cco, as I have quite a few clovers and ground ivy I want to tackle. Want to get some promiadine down as well, how important is it to calibrate my back pack sprayer?


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## Royale_with_cheese (Sep 10, 2019)

Bumping this thread


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## g-man (Jun 15, 2017)

Wait 2 weeks and then use something with triclopyr.

Yes calibrate the backpack sprayer and use proper PPE per the label.


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## Royale_with_cheese (Sep 10, 2019)

g-man said:


> Wait 2 weeks and then use something with triclopyr.
> 
> Yes calibrate the backpack sprayer and use proper PPE per the label.


Okay thank you.


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