Green Spots of grass in lawn

9 years ago

2 years ago, the lawn was killed completely, then re-killed 2 weeks later, everything was dead. What was planted was a 70/30 bluegrass/ryegrass mix. Last year we had a few brighter green spots, but this year it seems like more. The grass is fertilized with a 24-0-5 with iron.

Could the green spots be the ryegrass sticking around? Could it be one of the types of bluegrass? I have tried to id it a few times, (http://www.agry.purdue.edu/TURF/tool/index.html was helpful), and every time it comes up as a type of bluegrass. I don't see any pattern.

Can anyone help?

Comments (8)

andy10917
9 years ago
Those look like classic Poa Trivialis patches. Test by pulling out a handful - if it comes out easily and is fully of whitish root-like stuff that runs along the ground, it's Poa Triv.
gsweater
9 years ago
Indeed. Looks like PT for sure. Spray, kill, dig, spray, kill, dig, spray kill, dig. Eventually reseed. Ah, good times!
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bsimecek
Original Author
9 years ago
I will give it a pull tomorrow to check. Is your best guess that it came in the seed being that everything was killed or is the seed stay dormant for a while? this is the only "weed" that i have had a problem with since seeding.

Is there anything else that it could be?

Will MSMA kill it (assuming i was allowed to still use it) or is a Glyphosate only kind of fun?

Thanks for your help!
jos14h
9 years ago
Yep - poa Triv!

This is the worst nightmare for a lawn! The only way to get rid of it is to dig it up (at least 1 ft beyond the patch because the stolons go beyond the patch and then reseed or sod the area.

Round up (in multiple doses) and even tenacity don't totally kill it. Certainty may kill it but if you have tall fescue, it will kill it as well.

This is definitely the "weed" of the 21 century!! There are multi-million dollar lawsuits filed by golf courses against seed companies with contaminated poa triv since the only way to get rid of it is to renovate the entire area which is very expensive.

Don't waste your time finding the "chemical" to rid this crap!! Just dig it up and then follow good cultural practices ( cut high/keep the area dry) and do not buy cheap seed!! Buy only sod quality seed.
bsimecek
Original Author
9 years ago
From a purdue study, MSMA will work.
jos14h
9 years ago
What study did you see?

See this below

http://www.agry.purdue.edu/turf/report/1998/poatriv.pdf
bsimecek
Original Author
9 years ago
That would be the study...

"Many of the treatments caused phytotoxic damage to the
Poa trivialis turf. Treatments containing Daconate 6 (MSMA) generally caused the greatest amount of phytotoxicity."
jos14h
9 years ago
Read the results:

Single applications (0 weeks) and two application (0, 3 weeks), and most
treatments with three applications (0, 3, 6 weeks) did not reduce cover of Poa
trivialis compared to the untreated check (Table 1).

Based on the results of this experiment and the phytotoxic response of
creeping bentgrass to these same treatments it does not appear that any of
these treatments hold promise for effective control of Poa trivialis.