# Maybe a perennial Poa Annua biotype?



## nikmasteed (Apr 30, 2020)

I've struggled a bit to definitively ID this grassy weed that is established underneath a large crabapple tree. I've always thought it was poa annua, as it does produce those distinctive triangle-form seedheads in late spring. However, it never dies off in the heat of summer. Probably because of the shade (although this tree's canopy always allows some sun) and because I do water the lawn in summer. I read a UGA extension article that mentions that truly-annual biotypes of poa A stand straighter than perennial biotypes-- this stuff is definitely floppy as hell, so maybe its a perennial poa A?

To date I've been mostly content with avoiding drastic action (I'm not really into large renos in prominent areas of the yard). Last year I tried 2 apps of ethofumesate (poa constrictor) which did kill off a little of it over the winter. This year is the 2nd straight fall with prodiamine, although that doesn't do anything to the established stuff. It doesn't appear to be spreading.

I will probably glyphosate it in patches at a time, eventually. Unless anybody tells me I'm misidentifying and that there's a selective that could work....

Re: triv, I don't think its triv. I have that elsewhere, this is different


----------



## jha4aamu (Oct 16, 2017)

Not 100 percent sure on what it is but it almost looks like a warm season grass...maybe nimblewill. Do those spots take longer to greenup in the spring?


----------



## g-man (Jun 15, 2017)

I see stolons. That's not poa a. I can't see the leaf tip. Check against bentgrass.


----------



## Hawkeye_311 (Mar 8, 2021)

If it goes dormant before everything else this fall it's probably creeping bentgrass.


----------



## cleohioturf (Jul 20, 2020)

that looks like bent to me. Does it feel fluffy and when you spread it apart appear to almost open a wide canopy?


----------



## nikmasteed (Apr 30, 2020)

Thanks everyone! Bentgrass, eh? I'm not great at identifying but after researching a bit more, not sure that's it. I've added a few more pics, 2 closeups of the plant from today (including the blade tip @g-man ) , and some others from different times of the year.

Bentgrass apparently doesn't have a dominant middle vein on the blade, whereas this does. This stuff has not gone dormant during the summer/heat/drought. If you look at the pictures below it was yellowish during the dead of winter, and by the time March came around it was brown/dormant. That discoloration did NOT occur in winter 2019-20. I used ethofumesate in late fall 2020 so I figured what I was seeing was damage from those applications. At all other times since Nov 2019 it has been lime green.

A few more closeups:





Sept 16 2020-- in the middle of fall N blitz


January 14, 2021




March 20, 2021


April 11, 2021-- panicle seed heads. This also happened to be a few days after the 2nd of multiple 2oz/A Tenacity treatments (it did not die after 5 of these applications sprayed in April 2021)


Thanks in advance for any further thoughts on what this could be.


----------



## 2L8 (Mar 18, 2019)

Everything you have shown and described fits Poa supina. Only it is rather rare even in Europe and, as far as I know, does not occur naturally at all in the USA. Even the cultivated form is probably sold little there. Therefore it is probably, as you already suspected, a biotype of Poa annua.

Poa annua is believed to be a natural tetraploid cross of Poa supina and Poa infrima, which explains the high number of biotypes. Thus, the true annual biotypes are referred to as Poa annua var. annua and the perennial ones as Poa annua var. reptans. And reptans means creeping, so with stolons. (http://issg.org/database/species/ecology.asp?si=1418&fr=1&sts=&lang=EN)


----------



## Kissfromnick (Mar 25, 2019)

I had same problem time ago. I send samples for id to uconn it came back as poa t.


----------



## Kissfromnick (Mar 25, 2019)

I cant find copy of report but here picture of the samples i sent out.


----------



## nikmasteed (Apr 30, 2020)

Thanks. I don't believe this is triv, since this is distinctly different from the known triv I have elsewhere in the yard. But, maybe I'll send a sample out for ID as you did.

Any other thoughts from others? TIA


----------



## nikmasteed (Apr 30, 2020)

2L8 said:


> Everything you have shown and described fits Poa supina. Only it is rather rare even in Europe and, as far as I know, does not occur naturally at all in the USA. Even the cultivated form is probably sold little there. Therefore it is probably, as you already suspected, a biotype of Poa annua.
> 
> Poa annua is believed to be a natural tetraploid cross of Poa supina and Poa infrima, which explains the high number of biotypes. Thus, the true annual biotypes are referred to as Poa annua var. annua and the perennial ones as Poa annua var. reptans. And reptans means creeping, so with stolons. (http://issg.org/database/species/ecology.asp?si=1418&fr=1&sts=&lang=EN)


Very interesting, thanks!


----------



## nikmasteed (Apr 30, 2020)

Still struggling with this ID. Here's a bunch more pictures now several months later in early spring. The area on and at bottom of slope I sprayed in the fall (once) with ethofumesate. I avoided spraying above the slope to see the difference. You can see the impact the herbicide had, injured but not really dead (didn't get around to 2nd app in fall).

Anyway, struggling with the ID as I said. Id like to glyph it either way, but if it's triv I'll do it now for max success killing it, if it's not, I'll do it in the fall for better fescue growth.

I'm still a novice at reviewing these characteristics, I don't really know whether these ligules are membranous or absent (I think membranous). No auricles. Keeled boat-shaped leaf tips with single prominent vein. Panicle shaped seedheads showing NOW earliest its ever done that. I think it's bunch type growth.

Everytime I do more research on poa triv vs poa annua I get more confused, seems like different sources assign different characteristics to triv. An hour ago Id settled on triv, now I'm moving away from it again.

Help


----------



## 2L8 (Mar 18, 2019)

The last picture you have shown still makes me tend to Poa supina.

This can be seen by the relatively long anthers, which are somewhat shorter in Poa annua. In my lawn Poa supina is blooming since a few days:


But here the lawn consists of intentionally seeded Poa supina, because it is the best grass for the shade.

However, the anthers are still a little shorter, so it could be some variety between Poa annua and Poa supina, but with almost all the characteristics of Poa supina.

However, I am sure that it is not Poa trivialis.


----------



## Green (Dec 24, 2017)

Are those latest photos from today? I'm trying to understand when the seedheads were present. If it's got seedheads now in PA, it certainly is not Poa Triv.

I have no experience with Poa Supina.

As far as a Perennial biotype of Poa annua, I'd say it's still in contention, too. I have seen one in my own yard before. I have photos online somewhere...

In any case, this 100% a Poa/Bluegrass of some type.


----------



## Mark B (May 30, 2019)

Hi there,

The red purple panicle is a very strong identifier of poa supina.
If I understand correctly and those pictures are very recent then I will chime in and say that is poa supina, as it is in its flowering period now. You may also have other annua type grasses in that wider area.

I have grown supina for a few years in the 14mm to 32mm range. I don't see stolons when maintaining at 23mm. For me, it does not look good if left to go longer than that, and it seems that in your situation, the supina is a weed grass. If you scalp it low, keep it watered and fertilized, within three or four weeks it will really thicken well, however it will not blend with tttf or kbg.
It will out compete kbg. It will never be as dark as kbg, only expect a mid green at best.



Here is a link to this book with some information about poa supina for you, page 53.

https://www.google.co.uk/books/edition/_/L7kn1-aoXLIC?hl=en&gbpv=1

Hoping you can make the progress you desire.


----------



## nikmasteed (Apr 30, 2020)

@2L8 @Mark B Wow thank you so much for the knowledge on poa supina, very much appreciate the input given your experience with it across the pond. It seems like we just don't really have this here in the US

@Green @Mark B Yes all photos in my 3/25 post were taken on 3/25. I went back thru my photo archive and interestingly enough the earliest photos of this flowering in both 2020 and 2021 were on 4/11, although probably flowered several days earlier. In March 2021 it had not yet recovered from ethofumesate damage. In March 2020 I was just starting to learn about lawncare but did take many photos of the lawn and the seedheads would have drawn my attention.

Forgive my remaining slight skepticism only because I attempted yesterday to definitely find stolons in the effort to ID/rule out triv, and didn't really find above-ground stolons. I absolutely could be wrong but it seemed bunch-type to me. It also does not aggressively spread and in fact I don't think has spread much at all, although that could be due to the TTTF's dominance once you come out of the shade.

I plan to take some samples to the local Penn State extension office for further opinion, as the turf specialist there has agreed to aid identification. I'll try to do so while it's still flowering.

Long-term, I will almost certainly try to establish my 4th Millenium TTTF here. I want as much consistency as possible with the overall yard. This poa doesn't look bad most of the time just sticks out like a sore thumb in spring and fall. Since this isn't triv I'm not going to try a spring reno.

Since it seems as though Poa Supina is rare here, if anyone within driving distance is interested in cutting out sections for their own knowledge and/or use, feel free to hit me up.


----------



## VALawnNoob (Jun 9, 2020)

I have this in my yard. Is it possible Poa Supina was sometimes included in a Shade Mix?

Lastly, what is the best way to control Supina? From what is posted here it seems like we have to kill it the same as Triv? If so, why even bother identify it and just group it in same headache category as a Triv kill?


----------



## nikmasteed (Apr 30, 2020)

VALawnNoob said:


> I have this in my yard. Is it possible Poa Supina was sometimes included in a Shade Mix?
> 
> Lastly, what is the best way to control Supina? From what is posted here it seems like we have to kill it the same as Triv? If so, why even bother identify it and just group it in same headache category as a Triv kill?


If it is like triv in that spring is really the best time to kill it then I'd agree. It's definitely possible it came with a shade mix grown by previous owner. Although he was known to aggressively kill any poa in the fall, he would've done so here I suspect


----------



## nikmasteed (Apr 30, 2020)

Hi All-
I sent these photos as well as a physical sample to my local Penn State extension, where they confirmed that this is POA SUPINA. From the master gardener who reviewed the information and sample:

"Sample #1 Supina bluegrass (Poa Supina). You are correct. I confirmed this with your seed head photo. This variety is native to Europe (Germany and Austria) and is specifically designed for deep shade with little water."

Thanks again to those in Europe who chimed in offering this identification originally! Very much appreciated!!


----------



## Green (Dec 24, 2017)

Very interesting! @nikmasteed, you're going to be my go-to person to tag here in the US when someone posts about something that might be Supina, and everyone else says they have Triv or annua.

So, that makes 4 main "undesirable" Poa species that are relatively common:
-Annua
-Trivialis
-Bulbosa
-Supina

I've seen the first 3, personally. Probably never seen Supina. But I'm also pretty sure I've seen Poa Compressa, as well. And I know I've seen annua var. Reptans. Not to mention tons of Triv cultivars/biotypes.


----------



## VALawnNoob (Jun 9, 2020)

Green said:


> Very interesting! @nikmasteed, you're going to be my go-to person to tag here in the US when someone posts about something that might be Supina, and everyone else says they have Triv or annua.
> 
> So, that makes 4 main "undesirable" Poa species that are relatively common:
> -Annua
> ...


That's why I asked the question earlier. Why does it matter of it is Supina? It is still unsightly and something we want to get rid but can't easily. Isn't controlling Supina the same method as Trivialis?


----------



## Green (Dec 24, 2017)

VALawnNoob said:


> That's why I asked the question earlier. Why does it matter of it is Supina? It is still unsightly and something we want to get rid but can't easily. Isn't controlling Supina the same method as Trivialis?


Well, it looks as if Supina might be easier to control, for one thing (less spreading??). So that's one possible difference. This and the idea that Supina might be more common than people think. And it's just not accurate when everyone labels any weird Poa as annua or Triv, since there are definitely definitely others out there that are fairly common. Credit to the OP for not just being content thinking it was Triv and for being persistent to ID it accurately.

I have also definitely seen Poa Supina listed as an intentional component in off-the-shelf seed mixes, at least once or twice. So it's got to be more common than most think.


----------



## nikmasteed (Apr 30, 2020)

Well, the first step in understanding control options is ID. I didnt think it was triv, so was hopeful that upon an ID I would potentially have more options. Turns out not really, but that doesn't mean the ID wasn't worthwhile.

To confirm no known selective herbicide, see my further correspondence with PSU Extension below:

_"In terms of what to use to remove poa supina, I think you've cornered the possibilities. I'm sending a link to a scientific paper on the topic from 2002:

https://meridian.allenpress.com/jeh/article/20/2/118/79959/Tolerance-of-Supina-Bluegrass-to-Pre-and-Post

Of note: "Fall applications of Prograss (Ethofumesate) and Turflon Ester (Triclopyr) caused phytotoxicity the spring following autumn application in both years, while Strike 3 (Dicamba, MCPP, 2,4-D) and Confront (Triclopyr + Clopyralid) caused phytotoxicity in one year only. None of the compounds showed potential for selectively removing supina bluegrass from a mixed turf stand."

As you'll note, no formula or combination was successful in selective removal of poa supina."
_

The impact of ethofumesate described in the study is exactly what I have experienced. Temporary moderate phytotoxicity in the spring following fall application.

I'd still like to understand more, so again the ID was helpful to me-- for instance, it's usually recommended here to kill poa trivialis in the spring while it's growing. I suspect the same may be true for supina, but is it? Or since it's a shade tolerant grass and at least by my observation doesn't seem that different spring vs summer, maybe it doesn't matter. Maybe I'll try killing a spot in July to test it out. I'm certainly not doing it this spring because I've already got some triv to kill. Stay tuned....


----------



## nikmasteed (Apr 30, 2020)

Also @Green you'll note that the study mentions that poa supina was seeing increased use in athletic fields and shaded lawns in US, going from zero seed sales to several tons annually since 1990.

So it's definitely out there more than folks realize. Tag me all you want by the way :lol:


----------



## 2L8 (Mar 18, 2019)

Poa supina spreads mainly by stolons. It blooms only once in spring (here the flowering started about a week ago). The flowers are more upright than Poa annua and are thus better mowed down. I watched some separately growing Supina plants for weeks last year. It took about 3 weeks from flower panicle opening to seed maturity.

I have found very little Supina in the adjacent TTTF lawns so far.

Supina, like Triv, has its hardest time here in the summer. I have had patches dry up more often. Fine fescue has taken hold there. If I forget to water Supina in pots for a long time, they are dead and do not come back. I therefore believe that Supina can regenerate from the stolons worse than Triv, but I have not made any attempts to test this.


----------

