# Poa Trivialis or Annua?



## ThePowerTool

I'm still new to this but I've suspected for a little while that I have some sort of Poa problem in my back yard. I can't seem to tell the difference between Poa Trivialis and Annua. My initial thought was that it is Poa Trivialis because it is green in the winter, dies back in the summer, and seems to spread rather than clump; but when I uploaded these photos to a plant identification app, it said Poa Annua so now I'm not sure which it is. Please help!


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## McDiddles

Believe triv has a darker seed head. Annua is white.


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## cfinden

@ThePowerTool Not sure if this applies to you, but the shady seed mix I used on my lawn one year was full of Poa Trivialis (on purpose!). Hopefully not the case for you too.


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## ThePowerTool

@cfinden Nothing I have seeded intentionally includes triv, but I've only owned the house for a few years and the lawn has been around for almost 60. I'm pretty sure companies were intentionally adding it back then.


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## Green

It's hard to tell right now. Keep an eye on it over the next month or so. There are actually 3 major possibilities, and each looks a bit different:

-annua
-annua var reptans (perennial form)
-triv

The annua var repatans looks sort of intermediary between the other two. Both it and regular annua tend to be less dense than triv. As far as I can tell right now, it could be any of the three. Also note that there are many varieties of Triv that vary in appearance, as noted in this thread, which is loaded with photos: https://thelawnforum.com/viewtopic.php?t=2461


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## ThePowerTool

Thanks @Green I'll keep watching it. Last night I found another big patch in a different area of the lawn after the snow melted. I'm hoping to get it figured out quickly because my property is pretty shady and we get a good amount of rain so I'm hoping I can do a spring gly treatment followed by seeding. That way I could lay some pre-M in the fall and hopefully prevent it from coming in next year. Does that make sense to you?

I also found a little contradicting info when trying to ID it. In the Tom Green video, the plant he calls Poa Triv clearly has a distinct ligule, but I found a document from Purdue that states that Poa Annua has a ligule but triv does not. From what I can tell, the plant in my yard does not have a ligule. It is also a darker green than I would expect, though that might just be because it's contrasted against brown, dormant grass and white snow.


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## Green

Your plan makes sense. But it will be easier to glyphosate in April. It really comes to life then. I do 3 apps. Check my old posts.

@tgreen admits that you can't go by the presence or absence of a ligule, stolons, etc. because they're absent in some plants and at some times of year. It can be pretty confusing sometimes what is what, even KBG vs Triv at times.


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## tgreen

Agree it's a little early to make an ID now, especially that far north. That looks like annua but as @Green said keep your eye on it. You are coming into the time of year where ID becomes pretty easy. If the plant in question develops a large number of seed heads then it's annua. If it doesn't then it's something else. Also, triv will outgrow annua (and tall fescue and KBG) in the early spring.

BTW, both annua and triv have a ligule. The presence/ absence of a ligule can be useful in distinguishing KBG from Triv. I find in my own yard that when the triv is big and thriving then the ligule is huge and obvious upon close inspection. In the middle of summer or when triv is struggling and plant is spreading via stolons then the ligule can be hard to see.

Maybe post some more pics in a few weeks once weather warms if you still can't tell.


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## tgreen

Just remembered, you may not have seen this video. I show annua and triv. This may help you

https://www.youtube.com/watch?v=g1ez--AFMgQ


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## ThePowerTool

Thanks for the info @tgreen. I'll just have to be patient and vigilant. It's just hard to keep waiting when I just want to get out there after seeing only snow for the pasts 4 months! I'll check back in, when I get some more info.


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