>"it explains how Poa does NOT need light to germinate and will still grow under the canopy of other grasses. Is that true?" Absolutely. Want to have some fun? Google "poa annua + antarctic" You do not state where you live, but here in the Midwest, we can cheat mother nature a little sometimes. Most early to mid Augusts, day time temperature remain warm, but the nights are starting to get cooler. It is this time that here we can cheat and drop seeds. One needs to baby it very closely, to get germination and growth from the new seedlings with watering, but it can be done. Then 2 weeks after germination (around Labor Day +/-) drop Dimension, to prevent poa annua from germinating as soil temps drop into poa's preferred range. *Once again - cheating. Most say wait until 2 mows of the new seedlings before applying preM's, however Zach Reicher of Prudue / now Unv Of Neb studies shows cheating can be done. See link here http://www.jstor.org/discover/10.2307/3988908?uid=3739656&uid=2129&uid=2&uid=70&uid=4&uid=3739256&sid=55906481363 Tenacity can be used anytime during this period, including seed drop day, and should be applied regularly during the fall for best results. Then at last cut of the year, apply Dimension again when you winterize with nitrogen - to prevent that "poa annua + antarctic"

Thanks JJ. My other internet surfing suggests 2 applications in the fall are probably best. I'm with you though, still not sure when is the best soil temp or air temps to work off of for application dates. Also looks like there are so many varieties of the stuff it may take at least two or three years to get it under control. For what its worth, I have also been making the wrong decision by continuing to use my mulching mower and returning the clippings to the yard when the stuff is going to seed (duh). Next year, I'm going to bag during that two or three week period where its worst.

You know the saying, if it quacks like a duck it's a grass. Or whatever. Control is probably the first order of business. I'm assuming you have a standard tri-mix (Kentucky bluegrass, fescue, and rye) lawn. If that's wrong, let me know. Tenacity herbicide will at least control the P. annua, but fall effectiveness can be a bit questionable. Hopefully it'll zap it enough that it weakens and General Winter takes it out. If not, you can keep going in spring to weaken it before summer. I'm not sure about the quack's response to Tenacity, hopefully somebody else will chime in. It tends to be a long battle. Manual removal might help, but the stuff has probably dropped tens of thousands of seeds, which will be quite happy to sprout once the area is clear. If that's the case, pre-emergent is your best bet...since spring seedings tend to fail anyway. Late summer is the time to seed the lawn. At that time, when you seed, you can also use Tenacity as a pre-emergent that won't touch your grass seeds...but will do a serious number on P. annua (I'm not sure about quack).

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?