Mid July for you in buffalo ny

 

It's on the later side now even for me or g-man, but I'm doing mine. Being late doesn't mean you'll miss all of the germination. It's still worth it with like 2 months of germination temps remaining. Labor day would be crunch time here.

 

I think early is better. My soil temp hits 70°F historically around the end of Sep/early Oct. I am going to apply Prodiamine ~the third week of Sep.

 

Thanks for the replies but mid July...? I've never heard anything like that as it's not late summer/early fall as when pre emergents in general are recommend to be applied in the fall. I can't imagine how it would stay active in soil until well into September when soil temps get 70 and below.

 

I plan with the 5 day avg.

 

Yes I think that's a good idea, but the way I look at it, it's not too close to 70 soil temp, so Poa Annua can't germinate yet.....? I get it needs to be watered in but short of that it's just sitting in soil early and subject to heavy rains possibly before soil temps reach 70. Just my own thoughts, but I'll prob put down tomorrow am.

Thank you

 

Yes I think that's a good idea, but the way I look at it, it's not too close to 70 soil temp, so Poa Annua can't germinate yet.....? I get it needs to be watered in but short of that it's just sitting in soil early and subject to heavy rains possibly before soil temps reach 70. Just my own thoughts, but I'll prob put down tomorrow am.

Thank you

The way I look at it (oversimplifying but close enough): if KBG can germinate, annua probably can, too.

The late July through early November timing is for stopping almost every seed from germinating. Before the soil goes down to 70F, and after it goes below 50F. There are usually a few early germinating seeds, and a few late ones. If they germinate, that's another plant. Not all of us are going to be that obsessive, though. You do what you can.

There are also tricks, like spraying a post-M like Mesotrione in conjunction if you're late with your pre-M. It will generally kill stuff that has just germinated in the past couple of weeks and is too small to see, whether that's Poa annua now, crabgrass in early Spring, etc.

And of course other variables like the thicker your grass is, the drier it is, etc., the less germination you'll have on the earlier side.

Case in point: I didn't use a Spring pre-M this year, and pretty much didn't see any crabgrass until this week in some areas.

 

There is nothing magical about 70F. I don't know the source of that number.

Why late July for you? Because you want the protection before the seeds start to germinate and survive. Poa annual drops a ton of seeds. They don't care if it is 72F or 68F. They will care about moisture. Guess what normally happens in August? We start to get rain again. We also get lower summer temps and shorter daylight. These conditions that allow for the soil to remain moist and for the seeds to germinate and survive.

Do you want to guess when is the best time to seed KBG in your area? First week of August.

 

The sources for 70 deg soil temp for Poa Annua germination, I have read many times (university sites etc) and from Turf expects, as well as posts from members on this forum.

Here nor there, you both have some good logic, and I did apply it yesterday morning. This is nice info to think about for my future apps, as in August around here it's typically in the 80's and not much irrigation or cooler nights quite yet, hence why I haven't applied early August before.

I think I may start applying next year sometime earlier in August, so if the product allows, apply another app 6-8 weeks later to keep great preventative coverage well into the fall when Poa Annua germination is at its peak.

POA sucks!

Thanks for all guys.

I

 

This study is old and it was in Maryland, but check the conclusion.

https://gsr.lib.msu.edu/1990s/1999/990306.pdf

 

Thanks for sharing, I'm not sure if I read it all correctly, but sounds like that study showed best percentage of control was from end of August to mid September app's? If so, I'm right there this year as I just applied the other day.

 

In Maryland. 350miles south from you with a warmer weather. They likely cancel schools if there is 2in of snow vs 2ft.

 

Still battling poa A years after full reno with KBG. Never had it prior to that so jsut think the amount of watering needed to establish KBG was prime environment for poa to get established. I'm applying prodiamine now first week of August and again in late sept or early October. Then I'll bag vs mulch/side discharge when seed heads are evident. Making progress, but no where near solved yet. Have a few shady areas that show zero signs of progress though....the sunny parts of lawn are mostly poa free now.

 

Still battling poa A years after full reno with KBG. Never had it prior to that so jsut think the amount of watering needed to establish KBG was prime environment for poa to get established. I'm applying prodiamine now first week of August and again in late sept or early October. Then I'll bag vs mulch/side discharge when seed heads are evident. Making progress, but no where near solved yet. Have a few shady areas that show zero signs of progress though....the sunny parts of lawn are mostly poa free now.

You could have Perennial Poa annua. Does it ever die?

 

I am applying tomorrow in NE NC. I hope I am not too late. It's been hot!

 

I am applying tomorrow in NE NC. I hope I am not too late. It's been hot!

You're likely fine.

 

The deal is done! No fall over seed 2022! Hopefully that and another year of etho will kick poa in the teeth!

 

Thanks for posting that study, a lot of great points about poa-a. I got my pre-m down 1sr week of August, but really believe you can't go by all the rules of thumb on poa-a. No pre-m works 100%, some poa-a always gets though.

I swear some poa-a comes up in June, right after I have gone through my 16oz of tenacity. It's not that the tenacity didn't work, I swear it seems like the pre-m wore off and the poa-a germinated earLy spring

Right now I have some poa-a that made it through the summer and sending seed heads up. My KBG had a great year, It's never been so thick, but I can almost see the light green spots thriving from my 1st urea app.

I'll probably wait for either seed heads or next spring to pull them out, but it really is about having a year long barrier and a multi pronged approach to constantly go after the poa-a. Don't be afraid to split pre-m apps or put it down late.

 

This study is old and it was in Maryland, but check the conclusion.

https://gsr.lib.msu.edu/1990s/1999/990306.pdf

The interesting thing about this is……

It also is important to note that only the sprayable, 65DG formulation of prodiamine was evaluated. Granular forms of prodiamine may not perform as well as the 65DG. For example, numerous granular forms of prodia- mine have been tested for several years at the University of Maryland for pre- emergence smooth crabgrass control. These studies clearly have shown that there is a great variation in crabgrass control performance among the many granular forms of prodiamine available in the marketplace.

If you spray it, it coats the grass leaves, you water it, the water picks up the chemical as it falls to the ground and coats the soil.

If you have a granular product, you drop it directly on the soil, the water hits it and dissolves it, as it dissolves to coats the soil.

It's weird that granular wouldn't get more product coating the soil. Unless the coating itself doesn't dissolve as uniformly and spraying the lawn.

 

Would it be the same schedule for Nutsedge?

 

Would it be the same schedule for Nutsedge?

No, but mostly because Prodiamine doesn't do much to Nutsedge. Nutsedge can be treated post-emergently in a fairly wide window.