How about a picture?
Also what pre-emergent did you use?

Here you go.

Another image.

Last picture of the poa

And the pre emergent.

From what i read that is a good source as a generic barricade. This is a pre emergent only spray so something went wrong. Did you make it strong enough or maybe missed spraying were the poa currently is coming in?
I put dimension down this fall but have a few patches of poa that broke through somehow that i am trying to figure out. Since my bermuda is dormant still i spot sprayed some atrazine on that area about three weeks ago and it is just starting to work

Was August the last time you applied Prodiamine? If so that is why it didn't work. Poa is a Winter/Spring time weed, so you will need to make sure you have a weed barrier down to prevent it from growing. Prodiamine needs to be applied 2-4 times a year to have season long control depending on how much you apply per application. Just be sure not to go over the MAX yearly recommended amount.

P. annua, like any other weed, isn't perfectly controlled by a pre-emergent. It just makes the problem better, not gone, and P. annua can spread like crazy once sprouted.

For the most part, count on 80-90% control maximum from a pre-M, and only if you had good coverage at the time the weeds sprouted. Even with full coverage, I still get 2 to 3 small patches of P. annua or P. trivialis per year, but I then hit them with Tenacity.

Over time, you should notice the problem reducing in severity as the soil's reservoir of weed seeds slowly gets used up. That 2 or 3 of mine is down from 20 to 30. At least.

Hi All,

Thank you so much for the replies. Yes, August was the last time I applied the pre emergent (actually the only time). If poa grows in winter/spring, will doing another application now prevent add'l growth in spring?

Your August dose covered you through fall sprout, so that's good. That's when P. annua's major sprouting period happens--it's a fall/winter annual but can survive summers easily if watered, as with the rest of the lawn.

Depending on amounts used, that may cover you into spring as well, although I wouldn't count on that.

Given your weather--mid-seventies currently--weed sprout can actually happen at any time where you're located. I'd check the length of coverage and put more down a little before the old stuff is due to run out.

And be very sure to check the maximum allowed for your grass. If the next application in a calendar year is going to exceed that, use another pre-emergent instead.

Thank you so much!

I am trying to figure out the best schedule for my pre-M. I have bermuda during spring/summer and overseed with rye during fall/winter. My lawn is ~1400 sq ft. The Resolute 65WG herbicide I have indicates an annual max application of .36-.83 oz/1,000 sq ft for bermuda , and .18-.55 oz/1,000 sq ft for rye.

There is a special section in the instructions for application of poa annua control in established bermuda overseeded with rye that indicates using .18-.36 oz/1,000 sq ft 6-8 weeks before overseding, and a second application 4-8 weeks after overseeding.

Since the first section indicated a max application of .55 oz/1,000 sq ft on rye (even though my rye only exists for half the year), and the MINIMUM recommended application amount in the second section (for bermuda overseeded with rye) is .18 oz/1,000 sq ft, does this mean the maximum number of applications per year I can make is 3? (assuming I use the min .18 oz/1,000 sq ft/application amount and the max .55 oz/1,000 sq ft/year total allowable amount)

If I can only do 3 applications per year, and considering I overseed the rye in mid-october, I am thinking the pre-M applications should occur middle of August, middle of December, and middle of April. I am confident on the first two because they correspond with the 6-8 weeks before overseeding and the 4-8 weeks after overseeding specified in the instructions. However I'm not sure about the April application. Is April too late to do any good for spring P. annua?

The instructions on the bottle indicate that the .18 oz/sq ft application will only by effective for 3 months. So, 3 applications at 3 months each leaves me with only 9 months of coverage. Am I being too conservative on my max annual application amount (.55 oz/1,000 sq ft) considering I only have rye half the year? Should I be using the .83 oz/1,000 sq ft max annual amount associated with bermuda lawns instead?

>>I am thinking the pre-M applications should occur middle of August, middle of December, and middle of April. I am confident on the first two because they correspond with the 6-8 weeks before overseeding and the 4-8 weeks after overseeding specified in the instructions. However I'm not sure about the April application. Is April too late to do any good for spring P. annua?

That sounds about right. Your December application will cover you through March, so your April application picks up and covers through July.

Your open windows for seed sprout are July to August, plus a few weeks scattered here and there between the applications. Of those, the only one that would worry me is your November. However, the ryegrass has to age enough to tolerate the application, so you don't have a choice on that.

I think you chose the best possible applications--except I might be just a touch earlier on the April one since your weather is already very warm. Try to force the open period as much as you can into mid-summer.

Note: this is targeting P. annua control, which is a cool-season annual. If your problem were other weeds, I'd change the open periods around considerably.

>>Am I being too conservative on my max annual application amount (.55 oz/1,000 sq ft) considering I only have rye half the year? Should I be using the .83 oz/1,000 sq ft max annual amount associated with bermuda lawns instead?

Going higher has the potential to damage your rye--although your Bermuda would be entirely tolerant of it. While there's some give in the tolerances and they're set conservatively, I wouldn't risk it unless you're comfortable with the possibility of losing sections of ryegrass.