# Planning Ahead to Treat Poa Triv



## jpzsports (Jun 1, 2021)

Hello,

My KBG lawn unfortunately got various patches of poa triv throughout it during last fall. Once spring arrives, I hope to remove the poa triv and reseed some KBG. I would appreciate any advice. Can I just pull out the patches of poa triv and then reseed? Or do I need to spot spray glyphosate to kill it first? How long after spraying can I reseed those spots?

Also, typically I apply pre-emergent in the spring to prevent crabgrass. Since I need to work on reseeding these poa triv spots, do you think I should skip pre-emergent this year or perhaps apply it a few weeks after the new grass seed germinates? My lawn is definitely denser and healthier this year so maybe I can go without pre-emergent.

Any time frame recommendations would be helpful. I am in NH.

Thanks so much!


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## vancwa (Oct 28, 2021)

I'm sure others have experience with using pre-emergents. I don't, I deal with spots like this with spot spray of glyphosate. I have used marker paint to delineate the boundaries of the spots. It doesn't seem to bother the grass, and it helps me keep track of location as it grows and becomes more camouflaged among the desired lawn. Since it spreads, it's always good to spray a few inches beyond the boundaries. Then remove the dead debris and reseed the patches.

In my case, this is a multiyear battle but the patches are fewer and smaller. Good luck!


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## bernstem (Jan 16, 2018)

Pre-emergents will not stop or slow Triv. Pulling Triv will not kill it; it will regrow from the roots/stolons. Your best option is Glyphosate when it is actively growing. A single application of Glyphosate is unlikely to kill the triv completely. Do not be surprised if it comes back in later this year or even next year. Many members have resorted to painting individual Triv leaves/plants to minimze damage to the surrounding lawn. I don't have much, but anything that looks like Triv in my lawn gets dug up to 6 inches deep and 6+ inches around the patch if possible.


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## vancwa (Oct 28, 2021)

"A single application of Glyphosate is unlikely to kill the triv completely."

I agree with that! I would plan on 2 or 3 apps during the growing season to feel like it's gone, then seed the area in the fall. I'm sure digging 6" deep is a more thorough eradication, but I haven't resorted to that.


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## jpzsports (Jun 1, 2021)

Thank you all for the advice! This is very helpful. If I were to try to reseed after spraying and removing as much poa as possible, how long after using the Glyphosate should I wait before cutting out that grass and how long before seeding is safe?


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## stevehollx (Apr 8, 2020)

jpzsports said:


> Thank you all for the advice! This is very helpful. If I were to try to reseed after spraying and removing as much poa as possible, how long after using the Glyphosate should I wait before cutting out that grass and how long before seeding is safe?


You can add gly up to 3 days AFTER seeding. Last year I glypho'd about 1000 sqft of triv. Did 3 apps of gly + fertilizer across 17 days, and put seed down 1 hour after the third (final) gly app. I think I'm mostly Triv free at this point--spotted one area during a flush of winter rain not near an location I had it in last year. If any does come back it will be minimal compared to what I had last year. Will know in 1 mo since that's when the Triv flushes here, assuming we get some good rain.
https://thelawnforum.com/viewtopic.php?p=365616#p365616

Scalp it a few days after your first app of gly, since it will lay down and mat if you wait too long.

I've done some smaller spots where I just hit with 2 gly apps and seed goes right down with the second app after.

Iron is also a great way to identify Triv patches in the spring without spraying Tenacity. Helps you ensure you get the spots you need to.

Another cool trick--when you seed after killing the Triv spots, spray a ring of tenacity around the fringes beyond where you gly, and then if you miss any or it grows beyond the edge, it will light up and you can handle those spots. 1 Gly app and immediate seed over the top on young sprouted Triv seems to be enough to control (since you're getting close to summer temps by the time you'd see this, no time for more apps).


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## Old Hickory (Aug 19, 2019)

stevehollx said:


> I've done some smaller spots where I just hit with 2 gly apps and seed goes right down with the second app after.
> 
> Iron is also a great way to identify Triv patches in the spring without spraying Tenacity. Helps you ensure you get the spots you need to.
> 
> Another cool trick--when you seed after killing the Triv spots, spray a ring of tenacity around the fringes beyond where you gly, and then if you miss any or it grows beyond the edge, it will light up and you can handle those spots. 1 Gly app and immediate seed over the top on young sprouted Triv seems to be enough to control (since you're getting close to summer temps by the time you'd see this, no time for more apps).


This is very interesting. So you don't try to remove the treated triv, you just drop some seed on top of it? And you've had previous success with this?


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## jpzsports (Jun 1, 2021)

stevehollx said:


> You can add gly up to 3 days AFTER seeding. Last year I glypho'd about 1000 sqft of triv. Did 3 apps of gly + fertilizer across 17 days, and put seed down 1 hour after the third (final) gly app. I think I'm mostly Triv free at this point--spotted one area during a flush of winter rain not near an location I had it in last year. If any does come back it will be minimal compared to what I had last year. Will know in 1 mo since that's when the Triv flushes here, assuming we get some good rain.
> https://thelawnforum.com/viewtopic.php?p=365616#p365616
> 
> Scalp it a few days after your first app of gly, since it will lay down and mat if you wait too long.
> ...


This is helpful, thank you!

Do you think I can just cut out the poa triv areas and throw down some soil and seed or do I really need to apply the gly?


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## Lawn Noob (Jul 26, 2020)

I have begun just digging the triv patches out down the 3". Then I reseed.


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## stevehollx (Apr 8, 2020)

Old Hickory said:


> This is very interesting. So you don't try to remove the treated triv, you just drop some seed on top of it? And you've had previous success with this?


Correct-I'm chemically killing it, but not digging it out and removing. The dead Triv is actually preferred to hold the soil together and keep some moisture in.

I've even done just a total of 1 gly app+seed same day on immature spots that I have recognized that I saw late spring. So far no issues with seeing anything return.


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## Lurch (Jan 10, 2022)

When does Poa T normally return? Was thinking of doing a late fall burn and return this year to kill off problem areas


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## stevehollx (Apr 8, 2020)

Lurch said:


> When does Poa T normally return? Was thinking of doing a late fall burn and return this year to kill off problem areas


March for us in CLT, usually. Depends a bit on temps and rain. It loves BIG rains and then wakes up before fescue does. Spray iron in March to find it, as that will cause the lime green Poa to stick out (which is likely Poa T or Poa A).

I gly'd a big spot last Marsh (see my journal last year), seeded mid April. Held up pretty well and so far no signs of it back in those areas, but the next month is the real judgement. IMO even 1 app of gly with seed right over the top is better than waiting until Fall. A study somewhere showed Spring control of it was like 4x more effective than in the fall.


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## jpzsports (Jun 1, 2021)

Okay, so it is finally spring and I'm able to get a better look at these various patches in my lawn. Up close, it looks like healthy, green, dense grass. But it really stands out as patches among my KBG lawn due to it's slightly brighter green color and taller height. Any thoughts as to what grass type this is and what I should do about it? At first I assumed it was poa triv but I used the Picture This app and it thought it was Tall Fescue. I did sprinkle some Scotts sun/shade mix a bit last fall so is there a chance this is just young kbg?

What is the best treatment plan? Will it eventually blend into my lawn or am I better off cutting out the patches and seeding some KBG/PRG?

Appreciate the help!


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## rookie_in_VA (Sep 27, 2021)

jpzsports said:


> At first I assumed it was poa triv but I used the Picture This app and it thought it was Tall Fescue.


Fescue has prominent vertical veins. See pictures here: https://turf.purdue.edu/tall-fescue/ On your photos of the leaves I don't see the veins.


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## jpzsports (Jun 1, 2021)

rookie_in_VA said:


> Fescue has prominent vertical veins. See pictures here: https://turf.purdue.edu/tall-fescue/ On your photos of the leaves I don't see the veins.


Thanks! Makes sense. It does seem to have the characteristics of a bluegrass. Would you lean towards KBG or poa triv?


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## ABC123 (Jul 14, 2017)

year round pre emergent is very needed, apply it before the rate you applied is needed. lighter is needed because poa and other grasses can germinate quickly in the thatch


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## rookie_in_VA (Sep 27, 2021)

jpzsports said:


> rookie_in_VA said:
> 
> 
> > Fescue has prominent vertical veins. See pictures here: https://turf.purdue.edu/tall-fescue/ On your photos of the leaves I don't see the veins.
> ...


I am not sure. The Poa Triv in my lawn looks different: https://thelawnforum.com/viewtopic.php?f=33&t=34792 But perhaps the best next step is for you to pull out one individual clump and check the roots.


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## stevehollx (Apr 8, 2020)

This one looks like Triv to me.










You'll be able to spot the patches with some iron and a heavy rain as your lawn wakes up.


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## jpzsports (Jun 1, 2021)

Here are some more images from today. I have literally 50+ patches of this in my lawn. It has a shiny appearance and a slightly rubbery feel. Any chance it is just immature kbg? Or is it poa triv or poa annua?


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## Kissfromnick (Mar 25, 2019)

jpzsports said:


> Here are some more images from today. I have literally 50+ patches of this in my lawn. It has a shiny appearance and a slightly rubbery feel. Any chance it is just immature kbg? Or is it poa triv or poa annua?


I've been dealing with the same type of grass problem for a few seasons had many different responsible on this forum. End up to send the samples for gras Id to Uccon lab. Came back as poa T. Last season cut all areas out and replace with sod. Keep in mind 1app of round up Will make it look dead but it will come back next season.


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## Kissfromnick (Mar 25, 2019)

Also if you need temporary fix or don't wanna go crazy and kill reseed or dig out. 1 app of AMP XC Granular will make it look same as u ***. Here some pictures from last season.


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## jpzsports (Jun 1, 2021)

Thanks for the feedback. I appreciate it.

I'm leaning towards it being poa triv after the latest batch of photos. Now I'm debating what to do this spring. Do I still go ahead with pre-emergent now and just wait it out and see how to handle it in the fall? Or do I skip pre-emergent or at least skip the areas that have poa triv and rip out the poa and throw down some seed this spring?


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## Lawn Noob (Jul 26, 2020)

I sprayed out the poa with three rounds of glyphosate over 2 weeks and reseeded last Saturday.


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## Kissfromnick (Mar 25, 2019)

jpzsports said:


> Thanks for the feedback. I appreciate it.
> 
> I'm leaning towards it being poa triv after the latest batch of photos. Now I'm debating what to do this spring. Do I still go ahead with pre-emergent now and just wait it out and see how to handle it in the fall? Or do I skip pre-emergent or at least skip the areas that have poa triv and rip out the poa and throw down some seed this spring?


pre-emergent Will give you 0 result on triv. The best time to deal with triv is spring. If you decide to wait till fall most of you patches will go dormant over the summer and come back next spring in bigger size. Also keep in mind no spring fertilizer for triv areas it will boost triv to spread crazy


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## jpzsports (Jun 1, 2021)

So after further evaluation and feedback from several great resources, I can pretty much 99.9% confirm that these patches are poa triv. These patches are growing in shady, wet areas which triv likes and I also found some stolons.

I still plan on putting down my spring preemergent to prevent crabgrass over the coming months. Over the coming weeks, I will work on pulling out the patches of triv little by little and will put some top soil and seed in the bare spots and hope to get some new grass to fill in and my other grass to spread in as well. I'm hoping that by scraping up the dirt in those areas, I'll have some luck with seeding even though I will have already applied pre-em.


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## Lawn Noob (Jul 26, 2020)

jpzsports said:


> So after further evaluation and feedback from several great resources, I can pretty much 99.9% confirm that these patches are poa triv. These patches are growing in shady, wet areas which triv likes and I also found some stolons.
> 
> I still plan on putting down my spring preemergent to prevent crabgrass over the coming months. Over the coming weeks, I will work on pulling out the patches of triv little by little and will put some top soil and seed in the bare spots and hope to get some new grass to fill in and my other grass to spread in as well. I'm hoping that by scraping up the dirt in those areas, I'll have some luck with seeding even though I will have already applied pre-em.


Meanwhile, the ~100sf of triv at my place…



Seeded last Saturday. Should have new fescue coming up by tomorrow.


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## Kissfromnick (Mar 25, 2019)

jpzsports said:


> So after further evaluation and feedback from several great resources, I can pretty much 99.9% confirm that these patches are poa triv. These patches are growing in shady, wet areas which triv likes and I also found some stolons.
> 
> I still plan on putting down my spring preemergent to prevent crabgrass over the coming months. Over the coming weeks, I will work on pulling out the patches of triv little by little and will put some top soil and seed in the bare spots and hope to get some new grass to fill in and my other grass to spread in as well. I'm hoping that by scraping up the dirt in those areas, I'll have some luck with seeding even though I will have already applied pre-em.


Pulling out of triv wouldn't really work. Needs to dig out 2-3 inches down and minimum 12-14" around of visible triv. Stolons travel way more than actual plant you see if any stolons left it will regrow.


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## jpzsports (Jun 1, 2021)

Kissfromnick said:


> Pulling out of triv wouldn't really work. Needs to dig out 2-3 inches down and minimum 12-14" around of visible triv. Stolons travel way more than actual plant you see if any stolons left it will regrow.


Good advice, thank you!


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## 04gtod (Mar 23, 2019)

i wouldnt sod to repair poa triv. I repaired dog urine patches with sod and it is how i brought poa triv into my lawn. I would seed for the repair.


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## probara (9 mo ago)

I stumbled onto this thread searching for iron and poa. I applied some iron to even out lawn color and turned poa I didn't realize was there to a yellowish/brownish color.

It seems based on this video that high iron/low phosphorous may help suppress poa. Anyone have experience with this?

https://www.youtube.com/watch?v=dk_whyW2Qjg


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## EdenMd (7 mo ago)

Just wondering how jpzsports made out with Poa Triv control?? I found early Poa Triv in my lawn Oct 2022. Someone told me just pull it which I did. Pulled up easily like a carpet about 50 + patches. Filled the holes and reseeded. About 1/2 the areas now show some Poa on the perimeter. I'm not sure there is anything I can do this late in fall. Thought I would try glyphosate in spring just applying to what I see using a brush or foam applicator.


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