# Tenacity application w Aeration



## stacik84 (Feb 27, 2018)

Hi All,

Live in Boston MA. I am planning on spot treat my lawn with Tenacity...wait 3 weeks, then reseed and apply the 2nd application of Tenacity on the same day. Generally, is it appropriate to core aerate in between the two applications, or should I NOT break any soil barrier and just wait to aerate come this spring?

I had great results with reseeding springtime....used Black Beauty Ultra and Tupersan which I may try again. I am just hoping to provide better nutrients this fall AND especially tackle my weeds (crabgrass and poa annua) that is taking up about a 1/3rd of my lawn since the previous homeowners neglected doing so 

Any help appreciated!


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## Babameca (Jul 29, 2019)

@stacik84 Tenacity does not create soil barrier. It does not work as the prodiamine for example.
Tenacity does not have Poa A in the listed weeds to be controlled. I think you have to choose your battles. Either kill crabgrass and reseed, or apply Prem now (I think you are running late for it) and in spring that will control both weeds you have. I see you have tall fescue lawn, so if you are to fill in bare spots, you would be better with option 1 IMO.


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## Suburban Jungle Life (Mar 1, 2018)

Tenacity will suppress poa-a. You could use it as soil applied before the poa-a germinates, once more in 4 weeks, and then switch to prodiamine. You could also use ethofumesate to suppress poa-a. A combo of both are safe during seeding. To control the crabgrass, use prodiamine in the early spring. For now, you can use quinclorac to kill crabgrass if you want and it's also safe during seeding. These suggestions are for tall fescue.

I would use the above products and seed this fall. As for aeration, you could do it in the spring or right before seeding.


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## Drewmey (Oct 3, 2018)

Babameca said:


> Tenacity does not have Poa A in the listed weeds to be controlled.


It actually is listed but as suppression only.


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## ken-n-nancy (Jul 25, 2017)

Suburban Jungle Life said:


> Tenacity will suppress poa-a. You could use it as soil applied before the poa-a germinates, once more in 4 weeks, and then switch to prodiamine. You could also use ethofumesate to suppress poa-a. A combo of both are safe during seeding. To control the crabgrass, use prodiamine in the early spring. For now, you can use quinclorac to kill crabgrass if you want and it's also safe during seeding. These suggestions are for tall fescue.
> 
> I would use the above products and seed this fall. As for aeration, you could do it in the spring or right before seeding.


The above is good advice.

However, one item that is a little dependent upon grass type is the phrase "it's (quinclorac) also safe during seeding." See "Table 4" in the Drive XLR8 (quinclorac) label for guidance regarding use of Drive XLR8 around seeding time. (By the way, it is the most detailed chart I've seen regarding use of an herbicide around seeding time that I've seen on any herbicide -- kudos to BASF on the detailed info!) https://www.domyown.com/msds/Drive-XLR8-Label.pdf

Quick summary is to avoid Drive XLR8 (quinclorac) from 6 days before before seeding to 27 days after emergence for Kentucky bluegrass and fine fescue; and from shortly after seeding to 27 days after emergence for perennial ryegrass. Tall fescue doesn't have such a restriction, which sounds like it is what the OP has and for which @Suburban Jungle Life's advice is spot on (as usual.) I just didn't want another reader who has a northern mix to mis-apply the advice regarding quinclorac being safe around seeding.


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## stacik84 (Feb 27, 2018)

Since Tenacity doesn't create a barrier and only has a soil residual for a few weeks, could I apply the 1st application this week, aerate next week, reseed in 3 weeks while applying the 2nd application THEN use either prodiamine or dithiopyr 6-8weeks after germination?

Hoping mid-to-late October is not too late to use prodiamine or dithiopyr?...or will it even effect germination?


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## Suburban Jungle Life (Mar 1, 2018)

stacik84 said:


> Since Tenacity doesn't create a barrier and only has a soil residual for a few weeks, could I apply the 1st application this week, aerate next week, reseed in 3 weeks while applying the 2nd application THEN use either prodiamine or dithiopyr 6-8weeks after germination?
> 
> Hoping mid-to-late October is not too late to use prodiamine or dithiopyr?...or will it even effect germination?


I use tenacity at seeding since it does a good job preventing weeds while you are trying to grow grass. Since it only lasts a few weeks, weeds can start coming up after that so I then apply a second round. At this point, the annual limit is reached. A few weeks later, I put out prodiamine to prevent weeds for the rest of winter/spring. I would use quinclorac if you want to kill crabgrass now so you can save the tenacity for seeding and one more app a few weeks later. If you use it now and at seeding, then you could be fighting weeds on young grass.

I recommend this schedule:
quinclorac now if you want.
day of seeding: aerate, seed, tenacity at 8floz/A
seed should germinate in 1 week with sufficient moisture
4 weeks post germination: tenacity at 8floz/A
8 weeks post germination: prodiamine

Since you mentioned you have a poa-a problem, I would recommend adding ethofumesate to the above schedule.


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## Suburban Jungle Life (Mar 1, 2018)

ken-n-nancy said:


> See "Table 4" in the Drive XLR8 (quinclorac) label for guidance regarding use of Drive XLR8 around seeding time. (By the way, it is the most detailed chart I've seen regarding use of an herbicide around seeding time that I've seen on any herbicide -- kudos to BASF on the detailed info!) https://www.domyown.com/msds/Drive-XLR8-Label.pdf


Best chart ever! I wish they all did that.


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## Alias-Doe (Aug 9, 2019)

Suburban Jungle Life said:


> I recommend this schedule:
> quinclorac now if you want.
> day of seeding: aerate, seed, tenacity at 8floz/A
> seed should germinate in 1 week with sufficient moisture
> ...


I like this schedule . Do you use anything for fungicides after the 8 weeks?


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## Suburban Jungle Life (Mar 1, 2018)

Alias-Doe said:


> Do you use anything for fungicides after the 8 weeks ?


I don't. I tend to get fungus during seeding due to the constant moisture and warm temps. Probably pythium. I haven't seen any snow mold so once it cools off, I have no need for fungicide.


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## Babameca (Jul 29, 2019)

Suburban Jungle Life said:


> stacik84 said:
> 
> 
> > Since Tenacity doesn't create a barrier and only has a soil residual for a few weeks, could I apply the 1st application this week, aerate next week, reseed in 3 weeks while applying the 2nd application THEN use either prodiamine or dithiopyr 6-8weeks after germination?
> ...


IMO 8oz in a single app is a killer. Not in the sense it will kill anything. 4-5 is plenty enough even for the 'lazy' KBG.
Just watched Connor even go as low as 3oz on 2nd app...
This also leaves you plenty of ground to hit 3rd base (which I hope is not needed).
B


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## Suburban Jungle Life (Mar 1, 2018)

Babameca said:


> Suburban Jungle Life said:
> 
> 
> > stacik84 said:
> ...


I consider the label to be the law. The label clearly states to use a rate of 5-8 for seeding a lawn. Right below the chart of rates, it has a few sentences on resistance management and states to not use lower rates. Herbicide resistance is a big problem and the manufacturer has tested and listed the rates which are optimal for efficacy, reducing resistance, and minimizing environmental impact.

If there was a university study with proven results, I would consider alternate rates. Just keep in mind, you can sue the manufacturer if you use their product as labelled and it creates a problem. If you use it outside label rates, you can't blame them for any problems and you can be held liable.

If you want, you could use it at 5floz and use 3 apps. The annual max is 16floz. I feel 2 apps is enough to get establishment before switching to prodiamine. I'd rather use the higher rate to increase efficacy as long as it is within label rates.


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## Babameca (Jul 29, 2019)

@Suburban Jungle Life I agree with no going under label. I just gave the source for 3 oz as an example.
My experience with it is that it perfectly works at 5 oz. I also don't want to feel as a sergeon and in case I overlap accidentally to put way too much. It applies to anything I put on the lawn. And it costs less .
Cheers


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## Suburban Jungle Life (Mar 1, 2018)

Babameca said:


> @Suburban Jungle Life I agree with no going under label. I just gave the source for 3 oz as an example.
> My experience with it is that it perfectly works at 5 oz. I also don't want to feel as a sergeon and in case I overlap accidentally to put way too much. It applies to anything I put on the lawn. And it costs less .
> Cheers


My main focus is poa-a and it only supresses it so I use the max rate in hopes to improve results.

I do agree with you regarding overlap. I did on one strip and the turf wilted quite badly. Definitely gotta watch that.


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## Babameca (Jul 29, 2019)

@Suburban Jungle Life I see, It make sense...


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## stacik84 (Feb 27, 2018)

Suburban Jungle Life said:


> stacik84 said:
> 
> 
> > Since Tenacity doesn't create a barrier and only has a soil residual for a few weeks, could I apply the 1st application this week, aerate next week, reseed in 3 weeks while applying the 2nd application THEN use either prodiamine or dithiopyr 6-8weeks after germination?
> ...


Thanks Suburban Jungle Life!

I got delayed a little bit and just used Quinclorac last week. Crabgrass is already turning brown and dying! If I seed next week (mid Sept) and use Tenacity as described, how late is too late to apply Prodiamine. That times out to be Mid November. Is it still effective in the frost? I've also read that 8 shouldn't apply Prodiamine for atleast 4 months post seeding?

Thanks for the feedback


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## Suburban Jungle Life (Mar 1, 2018)

@stacik84 60 days after germination. If it's all frozen then, I wouldn't bother. No point putting anything on frozen ground.


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