# To Pre-M or not Pre-M



## Miller_Low_Life (Apr 12, 2017)

So lately I've found that pre-m is basically just for crabgrass.
I truly only have crab grass towards the street on the walkways.
Is it worth it to throw something like prodiamine down across the whole yard?
I do have a couple bags already so I'll do it anyways, but going forward into the future if I don't need it I'm done buying.


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## SNOWBOB11 (Aug 31, 2017)

I think pre-e's are a important part of a lawn maintenance schedule. Up until a couple years ago I never had a source for pre-e but now I do and I'm glad about that. IMO I wouldn't recommend skipping applying in the spring or fall.


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## Green (Dec 24, 2017)

My crabgrass pressure has decreased over the years in some areas, so most recently I've been investigating pre-Ms that target broadleaf weeds better and don't affect crabgrass, such as Gallery. I'll still need Dimension in most areas, like those where crabgrass from neighboring yards blows in, but I should be able to skip it in a few areas this year.


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## Jayray (Aug 8, 2018)

Miller_Low_Life said:


> So lately I've found that pre-m is basically just for crabgrass.
> I truly only have crab grass towards the street on the walkways.
> Is it worth it to throw something like prodiamine down across the whole yard?
> I do have a couple bags already so I'll do it anyways, but going forward into the future if I don't need it I'm done buying.


I'm in the same boat, I think the only reason I'm still considering it is for Poa control. I don't mind pulling crabgrass by hand I just don't have a way to control Poa.


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## mowww (Jan 16, 2018)

@Miller_Low_Life Are you interested in throwing down a sheet of plywood or small tarp during application and photographing a control plot throughout the season?

Hi from west Omaha!


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## wardconnor (Mar 25, 2017)

yeah do not skip Pre M. Good for POA and other general weeds.

Heck did you see what a difference it made in Barbs lawn. She has no winter weeds.


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## MarkAguglia (Jul 13, 2017)

Jayray said:


> Miller_Low_Life said:
> 
> 
> > So lately I've found that pre-m is basically just for crabgrass.
> ...


I'm in the same boat. Barely any crabgrass, could just pull it. Feel it's almost useless to do a spring pre-M since I only need to control Poa.


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## Kmartel (Feb 12, 2019)

Many of you say, you hardly have any crabgrass and you could pull it out by hand. But your all using a pre emergent, so you don't really know how much crabgrass you truly have.

I don't see anything good coming out of skipping a spring pre emergent unless you have some seeding to do.


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## mowww (Jan 16, 2018)

I will keep a 4x8 check plot free of PreM and document in my lawn journal throughout the season. Anywhere south of Nebraska and I would be nervous but we'll see how this turns out.


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## Chris LI (Oct 26, 2018)

Kmartel said:


> Many of you say, you. hardly have any crabgrass and you could pull it out by hand. But your all using a pre emergent, so you don't really know how much crabgrass you truly have.
> 
> I don't see anything good coming out of skipping a spring pre emergent unless you have some seeding to do.


Yes and no. Other than one tiny app of Prodiamine last fall (about 100 sq ft)and Tenacity once at seeding, I haven't applied a conventional PreM since 2005. I've applied corn gluten every spring since 2006 and rarely have to hand pick crabgrass. Even better, my adjacent neighbor upwind of me, cultivates a weed farm which consists primarily of crabgrass.

Initially, corn gluten was considered an organic PreM, but it's PreM attributes have been increasingly called into question, and it is now more thought of as a good fertilizer (9-0-0). Take it for what it's worth, but I'm quite happy with it.

Also, if I need to seed in the spring, I seed early enough to apply CG as the forsythia changes from the flowering stage (yellow) to the foliage stage (green). This year I dormant seeded, so I may only try a limited spot seed in April, if I'm not happy with the results.


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## Pete1313 (May 3, 2017)

Prodiamine is so cheap, especially if you spray, that I would never consider skipping it and not having that piece of mind unless you plan on seeding. At the 1.5 LB/A yearly limit, it is less than $0.50 per 1000 square feet.


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## Jayray (Aug 8, 2018)

Pete1313 said:


> Prodiamine is so cheap, especially if you spray, that I would never consider skipping it and not having that piece of mind unless you plan on seeding. At the 1.5 LB/A yearly limit, it is less than $0.50 per 1000 square feet.


It isn't so much the cost as it is the added chemicals to the lawn and also like @Greendoc mentioned in another thread there is a price you pay in root mass.


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## Jayray (Aug 8, 2018)

wardconnor said:


> Heck did you see what a difference it made in Barbs lawn. She has no winter weeds.


 :lol: Yes, when you use 10X the annual limit in one application I'm sure it works well.


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## Pete1313 (May 3, 2017)

Jayray said:


> It isn't so much the cost as it is the added chemicals to the lawn and also like @Greendoc mentioned in another thread there is a price you pay in root mass.


I get the preference to try and use less chemicals, but I personally wouldn't skip prodiamine for the fear of root pruning. There are far worse things I do, such as mow below 1", that have more of a negative impact on root mass. That being said, mowing low and using prodiamine, I have not seen any real negative issues on my root mass. Also keeping the amount of AI lower in the soil by using 2 or 3 split apps throughout the season provides control and lowers the risk of root pruning.


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## Miller_Low_Life (Apr 12, 2017)

mowww said:


> @Miller_Low_Life Are you interested in throwing down a sheet of plywood or small tarp during application and photographing a control plot throughout the season?
> 
> Hi from west Omaha!


Yeah I can do that.


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## Suburban Jungle Life (Mar 1, 2018)

Jayray said:


> I'm in the same boat, I think the only reason I'm still considering it is for Poa control. I don't mind pulling crabgrass by hand I just don't have a way to control Poa.


Ethofumesate? Tenacity?


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## Butter (Nov 14, 2017)

This will be my third spring in a row that I have not applied Pre-M. I forgot to do it once and I didn't really get much crabgrass. So last year I decided to roll the dice again. The only crabgrass last year was a couple spots that I repaired with commercially grown sod. So this year I'm gonna skip it again. This may come back to bite me because I disrupted the soil installing irrigation this summer. We will see. As far as fall Pre-M, its not used much in my area with my grass type, TTTF.


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## Jayray (Aug 8, 2018)

Suburban Jungle Life said:


> Jayray said:
> 
> 
> > I'm in the same boat, I think the only reason I'm still considering it is for Poa control. I don't mind pulling crabgrass by hand I just don't have a way to control Poa.
> ...


How effective is Tenacity against Poa as a pre-emegerent? Multiple applications of Tenacity has been useless against my pre-existing Poa. The only thing it has done is making it easier to find before the heads sprout so I can try to at least dig it out. I'll have to look into Ethofumesate.


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## Green (Dec 24, 2017)

Jayray said:


> How effective is Tenacity against Poa as a pre-emegerent? Multiple applications of Tenacity has been useless against my pre-existing Poa. The only thing it has done is making it easier to find before the heads sprout so I can try to at least dig it out. I'll have to look into Ethofumesate.


Tenacity is labeled for prevention of Poa annua germination, and is effective against it, but it has to be applied in the late Summer, and preferably followed up with Prodiamine or Dimension for best effectiveness.


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## Suburban Jungle Life (Mar 1, 2018)

Green said:


> Jayray said:
> 
> 
> > How effective is Tenacity against Poa as a pre-emegerent? Multiple applications of Tenacity has been useless against my pre-existing Poa. The only thing it has done is making it easier to find before the heads sprout so I can try to at least dig it out. I'll have to look into Ethofumesate.
> ...


 :thumbup:


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## steven harnois (Feb 19, 2019)

I've had good results using poa-constrictor in the fall applied at seeding in my fescue lawn, along with a follow up treatment according to the label a few weeks after germination. Controls poa well and doesn't seem to hurt the fescue germination.


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## j4c11 (Apr 30, 2017)

I think it depends on where you're at as well. Crabgrass is less of a concern for me these days, but I got wild bermuda seed floating around and I had issues with Virginia Buttonweed in the past.


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## FuzzeWuzze (Aug 25, 2017)

Question related to Pre-em...i sprayed about a 4 month rate of Prodiamine yesterday on my yard and rains didnt come as expected, so i turned on the sprinklers for 10 minutes tonight. I later noticed that a ton of water was running off presumably because my soil is already soggy. I'm now worried that a ton of the prodiamine ran off and didnt make it into the soil.


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