# T-Zone kills Poa annua



## jcs43920 (Jun 3, 2019)

Last week I was spraying weeds with T-zone and I figured why don't I just spray this on poa annua and see what happens. I know it's not on the label for grassy weeds but what the heck, might as well try. Well so far here is what happened.


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## Scagfreedom48z+ (Oct 6, 2018)

Interested to see if it bounces back or not. Did you increase the recommended rate? Any damage to the turf?


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## jcs43920 (Jun 3, 2019)

Scagfreedom48z+ said:


> Interested to see if it bounces back or not. Did you increase the recommended rate? Any damage to the turf?


Went with the 1.5 oz per gallon. Recommend was 1.25-1.5 oz. I had to take down some established creeping Charlie coming in from my neighbors property. I also used a surfactant.

Doesn't seem like there is any damage to the KBG around it but I also tried to avoid spraying it on anything other on the annua. I know it's the herbicide and not the poa dying in the heat because I left a few spots untreated since I wasn't sure about the experiment and they are healthy lime green. I'll hit those next and maybe do a second app on the other ones if they aren't completely knocked out.

Years ago when I first bought my house and didn't know much about lawn care I sprayed some weeds in my then creeping bentgrass infested yard with some Ortho 2-4-D, Dicamba, Quinclorac stuff from Home Depot. It left the wild violet and clover untouched but killed the bentgrass completely. It said it was guaranteed not to harm the lawn and I eventually figured it out that if broadleaf herbicide can kill bentgrass could it be possible that an even stronger herbicide with more chemicals selectively kill poa a?


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## Ben4Birdies (12 mo ago)

Hmmm... keep us updated! I'm sure many people will be interested if this works consistently.


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## Majahops (Sep 26, 2021)

Would love to see what would happen if you also hit some of the KBG on purpose. If it didn't die and poa did, you'd be the man.


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## ENVY23 (Sep 14, 2021)

This is interesting! I reno'd last year and had some weed pressure this spring since I didn't get a fall pre-m down. I did a blanket spray with TZone in April. Shortly thereafter, I noticed my Poa A was brown and was thinking "Is the Poa dying? It's been warm, but not warm enough to kill the Poa. Weird that it's dying so early in the season." I NEVER even considered the TZone may have had an effect on the Poa because I didn't notice anything on the label that's effective against Poa. Well since you posted this I guess now I know why it died. Yes, it's still gone and the KBG wasn't harmed, it's actually slowly filling in the dead spots. I'm interested to hear other's experience now.


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## Lawn Noob (Jul 26, 2020)

The heat hitting just about now also kills poa annua. How hot has it been there?


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## cleohioturf (Jul 20, 2020)

i think its the heat, honestly. northeast ohio has gotten a wave of heat the last few days, it got smoked. Even if it wasnt the heat alone it is probably a combo of the heat and chemical application.


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## jcs43920 (Jun 3, 2019)

Lawn Noob said:


> The heat hitting just about now also kills poa annua. How hot has it been there?


Mid 70s- early 80s still had 3/4-1 1/2 of rain each week. The untreated poa spots in my lawn are still alive and well. But not for long as I will spray them with T-zone just like I did the rest and hopefully get the same results.


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## jcs43920 (Jun 3, 2019)

Update

1 week out. Poa annua that was sprayed looks more like it's dying out. Still no damage to the KBG around it. I decided to spray all the poa in the yard this time and await the results. Here's some more pictures of it dying.


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## Ben4Birdies (12 mo ago)

@jcs43920 Thanks for the update. That looks really promising!

Has anyone else tried out the T-Zone on Poa annua? I'm looking into getting some.


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## vancwa (Oct 28, 2021)

Ben4Birdies said:


> Has anyone else tried out the T-Zone on Poa annua? I'm looking into getting some.


I don't have T-Zone but used Speedzone as a blanket spray in areas that had Poa A. Similarly, it turned light brown quickly, but seems to be bouncing back. I'm reluctant to do a spot second app because it may damage the nearby TTTF. If it does bounce back - I'm probably going with the "glove-in-glove" glyphosate treatment on the remaining Poa A. Definitely trying to bag up all the seeds during mowing to minimize re-establishment.


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## Mnbadger (Jun 9, 2019)

Any updates???? I have lots of Poa eagerly waiting your response!


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## jcs43920 (Jun 3, 2019)

Mnbadger said:


> Any updates???? I have lots of Poa eagerly waiting your response!


Sorry for the late reply. But yes it totally killed it. I did two applications and now It is all gone. Not a sight of it in my lawn. By the way the reason I was trying to kill it going into the summer is because I irrigate the lawn regularly and have seen annua stick around through the summer and into the fall. But I am definitely going to continue that approach from now on instead of dropping a 120$ on poa constructor that takes 21+ days to kill.


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## Green (Dec 24, 2017)

Spraying herbicides when it's getting hot out is always risky...it's possible to burn stuff out, like your grass. And T-Zone SE is a pretty hot mixture...of esters, Sulfentrazone, etc. Just Sulfentrazone alone can have negative effects on Poa annua and Triv...not to mention Tall Fescue, KBG, etc. I've seen many a pesticide applicator leave burn spots or tracks on neighborhood lawns this time of year from similar mixes.

In this case, it appears you hit the exact balancing point needed to knock out the bad Poa and leave everything else intact.

Please document everything you did (mix rates, application method, any adjuvants, time of day, etc.), and the weather conditions that day and that week...it may help someone else out in striking that balance in the future with this product!

Also, be careful...the results might not be as delineated every time.


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## ENVY23 (Sep 14, 2021)

^ Like I mentioned in my post above, I had the same experience as the OP with TZone on annua. I mistakenly said I applied it in April, but I just went through my notes and it was applied as a blanket spray on March 16th at 1.5oz per 1k. Soil temp at the time of application was 51° F. It was used in conjunction with an 80/20 nonionic surfactant. That's all I got for notes.

EDIT TO ADD: I'm a bit further south than most growing KBG, and as I mentioned I didn't get a fall pre-m down. The Poa A I had was pretty mature and already had seedheads at the time of application. I can vouch that it was NOT the heat that killed my Poa A. In addition to it only being March, my lawn was renovated last year and I was still watering somewhat frequently since the KBG was still young. My neighbor doesn't irrigate at all and still had Poa A for a while after mine was dead and gone, so if it was the heat his Poa would've for sure died too.


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## Scagfreedom48z+ (Oct 6, 2018)

ENVY23 said:


> ^ Like I mentioned in my post above, I had the same experience as the OP with TZone on annua. I mistakenly said I applied it in April, but I just went through my notes and it was applied as a blanket spray on March 16th at 1.5oz per 1k. Soil temp at the time of application was 51° F. It was used in conjunction with an 80/20 nonionic surfactant. That's all I got for notes.
> 
> EDIT TO ADD: I'm a bit further south than most growing KBG, and as I mentioned I didn't get a fall pre-m down. The Poa A I had was pretty mature and already had seedheads at the time of application. I can vouch that it was NOT the heat that killed my Poa A. In addition to it only being March, my lawn was renovated last year and I was still watering somewhat frequently since the KBG was still young. My neighbor doesn't irrigate at all and still had Poa A for a while after mine was dead and gone, so if it was the heat his Poa would've for sure died too.


Thanks for adding your experience. This might be a route I may take instead of using glypho this years Overseed, with the Poa a that survives throughout summer. How many apps did you make? Any injury to your existing grass?

I've been following this post since the OP started this, hopefully it expands


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## ENVY23 (Sep 14, 2021)

Scagfreedom48z+ said:


> Thanks for adding your experience. This might be a route I may take instead of using glypho this years Overseed, with the Poa a that survives throughout summer. How many apps did you make? Any injury to your existing grass?
> 
> I've been following this post since the OP started this, hopefully it expands


It was just the one app, no injury to my KBG and I did a blanket spray due to weed pressure I had at the time. It was my first time using TZone. Previously I would've used Weed B Gon Crabgrass mixed with Weed B Gon CCO, but I read here that ester based herbicides were more effective in cooler temps than animes, so I decided to get SpeedZone instead. While looking at SpeedZone on domyown, I saw that TZone contained triclopyr, which would save me from having to add it in, so I bought it instead. Kinda funny how it all happened and I unintentionally wiped out my poa a. lol


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## jcs43920 (Jun 3, 2019)

Green said:


> Spraying herbicides when it's getting hot out is always risky...it's possible to burn stuff out, like your grass. And T-Zone SE is a pretty hot mixture...of esters, Sulfentrazone, etc. Just Sulfentrazone alone can have negative effects on Poa annua and Triv...not to mention Tall Fescue, KBG, etc. I've seen many a pesticide applicator leave burn spots or tracks on neighborhood lawns this time of year from similar mixes.
> 
> In this case, it appears you hit the exact balancing point needed to knock out the bad Poa and leave everything else intact.
> 
> ...


Basically just did 
1.5oz per gallon of T-zone
1oz per gallon of non-inonic surfactant

Two applications spaced 7 days apart in mid-late May. Daily high Temperatures were between 70-82 degrees.

Supplemental irrigation with rain to get a total of
1-1.25 inches per week

Mixed it in a 2 gallon pump sprayer and spot sprayed in the evening

Blanket sprayed a couple areas where it was younger poa that hadn't become a cluster yet.

About 5 days after the first app I could tell it was either dying out of getting beat up.


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## Green (Dec 24, 2017)

jcs43920 said:


> Green said:
> 
> 
> > Spraying herbicides when it's getting hot out is always risky...it's possible to burn stuff out, like your grass. And T-Zone SE is a pretty hot mixture...of esters, Sulfentrazone, etc. Just Sulfentrazone alone can have negative effects on Poa annua and Triv...not to mention Tall Fescue, KBG, etc. I've seen many a pesticide applicator leave burn spots or tracks on neighborhood lawns this time of year from similar mixes.
> ...


Thanks. Good info. Very helpful.


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## Scagfreedom48z+ (Oct 6, 2018)

Is there a time requirement once tzone is applied before you can reseed? I know some herbicides have a waiting period.


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## Powhatan (Dec 15, 2017)

Scagfreedom48z+ said:


> Is there a time requirement once tzone is applied before you can reseed? I know some herbicides have a waiting period.


The label says ...

_*Reseeding Interval:*
Treated areas may be reseeded 3 weeks after application._


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## Scagfreedom48z+ (Oct 6, 2018)

Powhatan said:


> Scagfreedom48z+ said:
> 
> 
> > Is there a time requirement once tzone is applied before you can reseed? I know some herbicides have a waiting period.
> ...


Thanks for passing on the info


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## TheZMan (9 mo ago)

TZone in summer is pretty rough on cool season turfs types? Just wondering, haven't tried it.


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## tommydearest (9 mo ago)

TheZMan said:


> TZone in summer is pretty rough on cool season turfs types? Just wondering, haven't tried it.


It was a tad rough on areas of my KBG even in the spring. Pretty sure I applied a little over normal rate. But, from what I've read, the sulfentrazone can be a little rough on cool season grasses.


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