# Help with Poa annua invasion in zoysia lawn



## hefegrass (Mar 20, 2019)

I just bought a new home and moved in on Dec 7th. This is my first zoysia lawn, I have always had fescue lawns. When we looked at the house in late october the grass still had a little color and both front and rear lawns looked to be in great condition. We moved in and the next day we got snow which lasted several days. Then the entire winter has been rain non-stop. Now that its finally clearing up I recently noticed a patch of poa annua spreading from the edge of the lawn, very obvious because the zoysia is still dormant. At first i though it was my lawn greening up (noob with warm season or zoysia, or caring about my lawn), then i went out there to take a closer look and saw the seed heads. I did a little research and it turns out its poa (a few other weeds mixed in as well). Im assuming a pre emergent was never put down by the lawn service once the previous owners cancelled and moved. What can i do at this point?


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## Movingshrub (Jun 12, 2017)

Put down a pre em now no matter what.

You could leave it until it dies out with the heat.

If you want to spray it, simazine, monument, negate, and revolver are all contenders.

Negate is probably the cheapest. I am a big fan of multiple modes of multiple modes of action; think of trying to kill someone by shooting them, crushing them, and setting them on fire.

Simazine and negate have different modes
of action, would likely be one of the most cost effective options, and cover you for several years. I'm suggesting using both at the same time, incase that's unclear.


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## Spammage (Apr 30, 2017)

@hefegrass are you sure it's poa? That looks an awful lot like someone seeded some fescue or rye in that area ( maybe due to shade?). It also looks like your neighbor's yards.


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## hefegrass (Mar 20, 2019)

Movingshrub said:


> Put down a pre em now no matter what.
> 
> You could leave it until it dies out with the heat.
> 
> ...


thanks for the suggestions! 
I failed to mention earlier that i did lay down some prodiamine on march 2nd which will hopefully help me out later this summer. Would the negate/simazine be safe to use it right now even though spring green up is around the corner? I would only be spot applying, not getting the whole lawn. 
One more question: if im able to kill the poa, will my zoysia grow from these areas eventually or will i need to sod or plug? I am not sure what type of zoysia we have.



Spammage said:


> @hefegrass are you sure it's poa? That looks an awful lot like someone seeded some fescue or rye in that area ( maybe due to shade?). It also looks like your neighbor's yards.


I will get better pictures tomorrow. Im 90 percent sure its Poa, the seed heads and low bunch style growth seem like nothing else, but im no pro. All of my neighbors have fescue, which is green through the winter.. this patch of stuff just started to show up about a month or so ago.


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## Movingshrub (Jun 12, 2017)

Simazine is safe during green-up. I'm applying to my yard and it's starting to green-up.  before or after green up. Negate just got labeled for residential application. I'd be willing to take the risk personally. MSM is one of the active ingredients. I want to make sure I'm clear, hence the caps - IF A LITTLE IS GOOD, MORE IS NOT BETTER. You want to get a nice evenly applied application and not to overdose the area otherwise you're risking damage. Read the directions for everything sober, and well rested. Feel free to post your plan, and the application rates on here, before applying, so you get a sanity check.

@hefegrass 
Updated with some info I learned from greendoc. Siamzine either before or after green up, not during.


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## hefegrass (Mar 20, 2019)

Movingshrub said:


> Simazine is safe during green-up. I'm applying to my yard and it's starting to green-up. Negate just got labeled for residential application. I'd be willing to take the risk personally. MSM is one of the active ingredients. I want to make sure I'm clear, hence the caps - IF A LITTLE IS GOOD, MORE IS NOT BETTER. You want to get a nice evenly applied application and not to overdose the area otherwise you're risking damage. Read the directions for everything sober, and well rested. Feel free to post your plan, and the application rates on here, before applying, so you get a sanity check.


ok, thanks, ill check in before i apply anything. I also edited my last post while you were replying and added an additional question: if im able to kill the poa, will my zoysia grow from these areas eventually or will i need to sod or plug? I am not sure what type of zoysia we have.


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## Movingshrub (Jun 12, 2017)

It should spread. Make sure to manage expectations. If you have a plugger, you could do that to help it not have to cover as much distance. However, I wouldn't sod due to risk of it not matching your existing zoysia stand. You want it to be all uniform/same cultivar.


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## Movingshrub (Jun 12, 2017)

Just as a quick check before you buy anything. What post-emergents do you have on-hand? @hefegrass


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## high leverage (Jun 11, 2017)

Spammage said:


> @hefegrass are you sure it's poa? That looks an awful lot like someone seeded some fescue or rye in that area ( maybe due to shade?). It also looks like your neighbor's yards.


I too find it a bit odd to have an infestation of Poa in such a defined area. Color looks similar to what's across the street.


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## hefegrass (Mar 20, 2019)

Movingshrub said:


> Just as a quick check before you buy anything. What post-emergents do you have on-hand? @hefegrass


I have nothing on hand for post emergence except 2,4d and roundup



high leverage said:


> Spammage said:
> 
> 
> > @hefegrass are you sure it's poa? That looks an awful lot like someone seeded some fescue or rye in that area ( maybe due to shade?). It also looks like your neighbor's yards.
> ...


i should post a picture of my neighbors "lawn" and that might explain whats happening. I am pretty sure it is not a seeded cool season grass. I will take some close up pictures tomorrow. The poa is in some other spots as well, just very concentrated in that patch.


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## SCGrassMan (Dec 17, 2017)

Do not spot treat. Do a blanket application.


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## Movingshrub (Jun 12, 2017)

SCGrassMan said:


> Do not spot treat. Do a blanket application.


This.

Spray the entire yard. There is stuff you can't see that is there. Those products have a soil residual which will also help control other weeds from popping up.


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## SGrabs33 (Feb 13, 2017)

@hefegrass Nice to have another member from the Raleigh area on TLF!

I've got a pro plugger you can borrow if you want once you get your infestation under control. The Zoysia should fill in itself but depending on which cultivar it is it could take a while.


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## sanders4617 (Jul 9, 2018)

The Bermuda Triangle (or Bible), lists Celsius and Certainty as the 2 herbicides that should cover everything. I know that Certainty lists Poa Annua as one of the weeds it will control. What has been the experience on using that for Poa?

I've purchased both Celsius and Certainty myself. I wish I had just went and sprayed the Poa with glyphosate back at end of February. I had no clue that March would be colder than Feb lol. And my Bermuda has not shown 1 bit of life yet.

Slightly off topic... It's kind of interesting. We had the cold at beginning of March (lows near 20), and then this past week, we had 2 nights down to 25. So all the Bermuda in my neighborhood is still completely brown. But when I get into the Birmingham city area, its a completely different story. Plenty of green up. Shows how not only do we have micro climates in our lawn, but also in our regions. Was 25 here the other night, but didn't get below freezing just 20 miles away.

But I say all that to say that I should have just sprayed glyphosate lol.


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## Movingshrub (Jun 12, 2017)

@sanders4617 Those two products should cover most everything, but not everything.

Certainty will likely take multiple applications. Would any of us intentionally take weaker antibiotics knowing they are unlikely to do the job but willing to take for 20-30 days at a time instead of the ideal one for 10 days?

http://www.mobileweedmanual.com/search-weed.aspx?SpeciesType=Turfgrass&PrePost=Post&TurfGrass=4&OrnamentalType=&Ornamental=&OrnamentalName=&WeedType=Grassy&WID=70


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## hefegrass (Mar 20, 2019)

thanks for the help and suggestions everyone, i have some simazine on the way and will apply it as soon as it arrives..I also ordered negate but it says it will be a couple weeks.
I feel like i should rename this thread after going out and looking at the weed patch today. 
I went out this morning to take some pictures of the green patch and it turns out to be made up of mostly this broadleaf weed..is it carolina geranium? Last time i took a close look at the patch it seemed to be almost all poa annua but now there are very large areas made up of these broadleafs..completely covering the zoysia. 
Does this change what course of action i should take? this patch is growing larger by the day


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## sanders4617 (Jul 9, 2018)

@Movingshrub I love that.. thanks for sharing that. Been looking for something like that.


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## hefegrass (Mar 20, 2019)

Movingshrub said:


> SCGrassMan said:
> 
> 
> > Do not spot treat. Do a blanket application.
> ...


I plan on doing a spray of the simazine on the whole lawn tomorrow once it is dry out..I am unsure when the negate will arrive. Any problems with me doind them separately?


SGrabs33 said:


> @hefegrass Nice to have another member from the Raleigh area on TLF!
> 
> I've got a pro plugger you can borrow if you want once you get your infestation under control. The Zoysia should fill in itself but depending on which cultivar it is it could take a while.


thanks for the welcome and kind offer, hopefully I can get this knocked out and start thinking about plugging soon. I wish I would have checked locally before I ordered my reel mower online.


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## Movingshrub (Jun 12, 2017)

Doing them separately is fine.


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## SGrabs33 (Feb 13, 2017)

@hefegrass no worries, happy to help if you ever have issues :thumbup: please reach out if you ever want to borrow the plugger.


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## hefegrass (Mar 20, 2019)

ended up putting down simazine and then today I spot treated with certainty
At this point i just want to get it out of the lawn so my grass stands a chance at getting some sun..


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## hefegrass (Mar 20, 2019)

the Poa annua is strarting to show signs of death.
i really hope my grass underneath this layer of poa still has a little life left in it







here is a non-weedy section of the lawn:


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## hefegrass (Mar 20, 2019)

Movingshrub said:


> Simazine is safe during green-up. I'm applying to my yard and it's starting to green-up.  before or after green up. Negate just got labeled for residential application. I'd be willing to take the risk personally. MSM is one of the active ingredients. I want to make sure I'm clear, hence the caps - IF A LITTLE IS GOOD, MORE IS NOT BETTER. You want to get a nice evenly applied application and not to overdose the area otherwise you're risking damage. Read the directions for everything sober, and well rested. Feel free to post your plan, and the application rates on here, before applying, so you get a sanity check.
> 
> @hefegrass
> Updated with some info I learned from greendoc. Siamzine either before or after green up, not during.


oops..I went with your advice and sprayed it 
just went to look at this thread again and noticed the edit..


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## Movingshrub (Jun 12, 2017)

@hefegrass It's just starting to green-up in Alabama. I assume you're behind us on weather. Hope it does well.


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## hefegrass (Mar 20, 2019)

Movingshrub said:


> @hefegrass It's just starting to green-up in Alabama. I assume you're behind us on weather. Hope it does well.


i think its going to be fine. Maybe slower greenup but I have nothing to compare it to since this is my first year at this house and all the neighbors have fescue

i only sprayed simazine in the front and a small strip in the backyard, so far the front is greening up first (lots of sun)..and the backyard is slow to green up. I dont see any difference in the strip that was sprayed vs the rest of the backyard.


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## SCGrassMan (Dec 17, 2017)

hefegrass said:


> ended up putting down simazine and then today I spot treated with certainty
> At this point i just want to get it out of the lawn so my grass stands a chance at getting some sun..


We had specifically recommended a blanket app


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## hefegrass (Mar 20, 2019)

SCGrassMan said:


> hefegrass said:
> 
> 
> > ended up putting down simazine and then today I spot treated with certainty
> ...


i did a blanket app of simazine which was recommended .


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## hefegrass (Mar 20, 2019)

the POA patch is slowly dying and the grass is coming through, i think the patch will be totally gone within a month or two, then i need to stay up on my pre-m game


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## hefegrass (Mar 20, 2019)

closeup, dead poa, live zoysia
thanks to certainty


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## hefegrass (Mar 20, 2019)

figured I would post one more update, of the chemicals i sprayed the Certainty really did a grea job and didnt seem to effect the zoysia much. here is the current state of my front lawn, all fo the poa is dead and zoysia is quickly taking over!
the patchy area on the left is where the poa was, the bare looking spots are just sand from filling a couple holes and low spots the other day.


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