Are you guys having Pre-EM put down yet?

[jvanvliet]

We are overgrown with weeds, the squirt guys don't want to put down the pre-em yet. I think it may be too late, seed has germinated and we are in full bloom.

Any thoughts?

[williams lcm]

I put crab grass pre-emergent down on my lawn this past Saturday. I do have a fert company taking care of the lawn. I figure a little extra pre emergent for crab grass wont hurt. The bag says put down during the month of Feb than again 60 to 90 days after that. Not one weed in my lawn now. I have a good fert company.

[jvanvliet]

great site

http://greencastonline.com

[bugsNbows]

Lots of variables here. Some products work on several weed species, some are mainly crabgrass products. With a mild winter, the crabgrass wasn't banged much, so it's cranking now. Some products have treatment restrictions regarding applications or amounts applied per growing season. If applied too early, they may actually "play out" and by mid-summer be gone. Timing is critical to be sure. We have just started first apps as of Feb.

[Ric]

Originally Posted by bugsNbows

Lots of variables here. Some products work on several weed species, some are mainly crabgrass products. With a mild winter, the crabgrass wasn't banged much, so it's cranking now. Some products have treatment restrictions regarding applications or amounts applied per growing season. If applied too early, they may actually "play out" and by mid-summer be gone. Timing is critical to be sure. We have just started first apps as of Feb.

Great Point

Location Location Location plays a super important part with Pre Emege. 10 to 20 miles can be weeks a part with spring flush and Pre Emege timing.

In years past I have followed the non Pre Emerge policy believing it chemically root pruned my St Augustine. Now I am trying it the other way against my original opinion of Root Pruning being more harmful than good.


.

[rob7233]

What would be the general effectiveness "window" of the typical or most preemergent products to prevent weed seed germination either in bedding areas or in turf?

Also, would that be the same for any potential root pruning results for SA?

[Landscape Poet]

Originally Posted by rob7233

What would be the general effectiveness "window" of the typical or most preemergent products to prevent weed seed germination either in bedding areas or in turf?

That would be determined by the AI and the targeted pest in terms to the "window" .

[bugsNbows]

Originally Posted by Ric

Great Point

Location Location Location plays a super important part with Pre Emege. 10 to 20 miles can be weeks a part with spring flush and Pre Emege timing.

In years past I have followed the non Pre Emerge policy believing it chemically root pruned my St Augustine. Now I am trying it the other way against my original opinion of Root Pruning being more harmful than good.


.

We have observed both root pruning and looping from Pre-emergents in SA. Seems like Dimension was exhibiting such as much as any of the other products. I guess one needs to weigh all considerations (risk vs. benefit) and make a choice. We will likely run two cycles then that's it. When it's gone it's gone. I've always felt that the one big problem with pre-emergent turf apps is...you never know for sure what the conditions would have been like had you NOT applied any (unless you do half with and half without in side-by-side comparisons). Just give it your best shot, inspect often , document your findings and then run like hell!!! LOL.

[jvanvliet]

The window varies with the Zone, end of February is typical down here.

I believe the target application date may have changed in light of the weather conditions, an earlier application is indicated since seed germination is exceeding the threshold levels down here.

Problem is, what does it do to later applications and the window involved. Do you move the second application up proportionately and run the risk a later application being required and having maxed the limits? Or risk the window between applications and spot spray knowing seed has already germinated.

The reason I ask is because I'm expected to inform several HO's regarding the turf conditions and make recommendations. I haven't experienced this type of winter.

I'm inclined to recommend an immediate application now. Split the time difference between now and the next application and bank on a normal cool season this year.

[Landscape Poet]

Originally Posted by jvanvliet

The window varies with the Zone, end of February is typical down here.

I believe the target application date may have changed in light of the weather conditions, an earlier application is indicated since seed germination is exceeding the threshold levels down here.

Problem is, what does it do to later applications and the window involved. Do you move the second application up proportionately and run the risk a later application being required and having maxed the limits? Or risk the window between applications and spot spray knowing seed has already germinated.

The reason I ask is because I'm expected to inform several HO's regarding the turf conditions and make recommendations. I haven't experienced this type of winter.

I'm inclined to recommend an immediate application now. Split the time difference between now and the next application and bank on a normal cool season this year.

Jvan -

Again my advice would not be based on zone but rather the weed you are concerned about, the product going to be used and it's AI, and in most cases I would assume the soil temps.
If you are concerned about the weeds you are seeing now - those guys have germinated obviously - what good is putting down a Pre-em going to do? I am failing to understand the concern on this part.
Last but not least - why are the HO's relying on you to tell them about turf conditions and recommendations. Should their L and O company not be doing that for them? Why are they asking you for recommendations on something you have no input on. I could understand them asking if you think there company is doing a good job in your opinion or if you know of someone who can do better but not asking for a prescription for their lawn.