# Will spring Pre-emergent application affect fall overseed?



## ceriano (Oct 6, 2021)

Will spring perm affect fall over seed? Is dimension a better option over prodiamine if major fall over seed is in the plan?


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## SNOWBOB11 (Aug 31, 2017)

If you go on the lower side of spring application it should pretty much wear off by the fall. I know many people on the forum have seeded in the fall after a spring application. You should be fine just read the label to get the proper application rate for when you want it to wear off.


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## 440mag (Jan 29, 2018)

I simply read the label and measure out the appropriate (designated) amount for 4-6 months coverage; and since I apply around Valentines Day (and no matter what as far before Mar 1 as possible!) I am always weed free through July-August which is perfect as I start my over-seeding September and October …

https://www.domyown.com/msds/Prodiamine_65_WDG_Label.pdf

https://www.pestrong.com/attachment.php?id_attachment=426

https://www.pestrong.com/attachment.php?id_attachment=437

Here also is a good reference on Pre-Emerg's and their MOA's (article pertains to appl. on KBG but notwithstanding, info on MOA's can be useful to many / most …):

https://aggieturf.tamu.edu/wp-content/uploads/ESC036.pdf

If you're gonna err on one side of early or late application I always err on the side of early! (In fact, starting next year (2023) we will begin wintering in FL every Jan thru March so, I will be applying my pre-emerg during the frequent (you-can-count-on) nice, warm days we enjoy every December!

I may do a split app (max Prodiamine app in late December and appropriate (3-month) app of Dithiopyr in mid April but, NO WAY I would ever wait until we return from FL in April to do any pre-emerg and especially since the NCSU Turf Files paper published a couple years ago where research evidenced certain problematic weeds (I.e., crabgrass) sprouting earlier and earlier and at lower soil temps than historically chronicled. I will post the link to that publication if I can find it amongst the hundreds of references I've bookmarked since joining TLF :thumbup:

It may work for others (color me indubitably in-dubious) but, "_waiting to see the forsythias bloom_" has proven to be nothing short of a complete Failure Path for me, both when in Southern Maryland-Stan and now in WNC

SIMILARLY, do NOT let the "Utah" in this articles title dissuade you from benefiting from all the article contains; not the least of which is the handy dandy reference tables on pages 5 and 6 (printed and hanging in plastic sheet protectors on the inside of my chem cabinet door!!!!)

Weed Control Options for Residential Lawns in Utah: https://digitalcommons.usu.edu/cgi/viewcontent.cgi?article=1774&context=extension_curall


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## ceriano (Oct 6, 2021)

440mag said:


> I simply read the label and measure out the appropriate (designated) amount for 4-6 months coverage; and since I apply around Valentines Day (and no matter what as far before Mar 1 as possible!) I am always weed free through July-August which is perfect as I start my over-seeding September and October …
> 
> https://www.domyown.com/msds/Prodiamine_65_WDG_Label.pdf
> 
> ...


This is very helpful thank you! Does Prodiamine have any adverse effect on new grass roots? I did a Reno. in October, theoretically grass only had about a couple of months to grow. 
It is still patchy in some areas so I probably need to do another overseed in the Fall.


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## Babameca (Jul 29, 2019)

@ceriano Very challenging to do Prodiamine with any grass type that needs seasonal overseeding. Prodiamine works on roots inhibition, so Yes, serious effect on roots developpement when active. I think Dimension may suit better your needs on the long run.


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## ceriano (Oct 6, 2021)

Babameca said:


> @ceriano Very challenging to do Prodiamine with any grass type that needs seasonal overseeding. Prodiamine works on roots inhibition, so Yes, serious effect on roots developpement when active. I think Dimension may suit better your needs on the long run.


Thanks that makes sense. some suggest waiting a full year before doing any prem.


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## Lawn Whisperer (Feb 15, 2021)

From the labels:

Prodiamine - "… wait 60 days after seeding or until after the second mowing, whichever is longer, before applying Prodiamine…"

Dithiopyr (Dimension) - "Newly established turf must have developed a good root system and a uniform stand, and have received at least two mowings following seeding or sprigging before making the first application of this product."


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## bernstem (Jan 16, 2018)

Babameca said:


> @ceriano Very challenging to do Prodiamine with any grass type that needs seasonal overseeding. Prodiamine works on roots inhibition, so Yes, serious effect on roots developpement when active. I think Dimension may suit better your needs on the long run.


Dimension also inhibits root growth. Both Dithiopyr (Dimension) and Barricade (Prodiamine) work by inhibiting cell division through blocking of microtubule growth, though the specific mechanism is different.


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## Scagfreedom48z+ (Oct 6, 2018)

I've never had an issue. I'm also disturbing the soil layer and breaking the barrier by dethatching and scarifying the soil. I've overseeded the last 3 seasons


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## Babameca (Jul 29, 2019)

@bernstem What I meant is that Dimension lasts way less, where Prodiamine should be applied with a very high precision at min rate, at least where I live... in order to have the perfect seeding window.


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## bernstem (Jan 16, 2018)

Babameca said:


> @bernstem What I meant is that Dimension lasts way less, where Prodiamine should be applied with a very high precision at min rate, at least where I live... in order to have the perfect seeding window.


I clearly misread your statement - apologies.


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## g-man (Jun 15, 2017)

Babameca said:


> @bernstem What I meant is that Dimension lasts way less, where Prodiamine should be applied with a very high precision at min rate, at least where I live... in order to have the perfect seeding window.


I don't think the data aligns with way less, maybe just a bit less.

https://turf.purdue.edu/wp-content/uploads/2012/06/15_AGRY_Patton_sequential20apps.pdf

Regardless, rate and application timing matters for an overseed. For a renovation, i would not risk doing spring prem.


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## bernstem (Jan 16, 2018)

While @g-man's linked study seems to suggest the impact on a fall overseed will be similar with Dimension and Prodiamine using a split application, I would be very careful generalizing Crabgrass control data to fall grass seed germination rates.

Regardless of details, the point remains. I also would not pre-em for a renovation and would watch application rates and timing carefully if planning to overseed.


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## Babameca (Jul 29, 2019)

@bernstem I was the one not being clear in my original reply. All good.


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## Jeff_MI84 (Sep 28, 2020)

@bernstem if you wouldn't put down pre-emergent the year you're doing a reno, would you stay on top of post-emergents or just say the heck with it?


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## Zimmerman (May 20, 2019)

I just read the first two posts and agree totally.


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## ceriano (Oct 6, 2021)

Jeff_MI84 said:


> @bernstem if you wouldn't put down pre-emergent the year you're doing a reno, would you stay on top of post-emergents or just say the heck with it?


Correct me if I'm wrong but the types of weeds PREM prevents this time of year are not very hard to kill post EM anyways, right?


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## bernstem (Jan 16, 2018)

ceriano said:


> Jeff_MI84 said:
> 
> 
> > @bernstem if you wouldn't put down pre-emergent the year you're doing a reno, would you stay on top of post-emergents or just say the heck with it?
> ...


For a renovation, you are going to Glyphosate the whole yard and kill everything so there isn't any need to prevent spring weeds from germinating. Since glyphosate kills (nearly) everything, the weeds are easy to kill. The lawn may have more weeds than a typical year, but as long as they don't go to seed it won't matter in the long run.


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## ceriano (Oct 6, 2021)

bernstem said:


> ceriano said:
> 
> 
> > Jeff_MI84 said:
> ...


Correct! For my lawn I'm planning to do a heavy overseed next fall. There are some areas that are still very thin from last falls Reno.


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