# Prodiamine and dithiopyr



## Theycallmemrr (May 16, 2019)

I am trying to set myself up for a great next season and it was recommended to me to do split pre emergent applications of prodiamine and then dithopyr. That way I can max out on each and get longer protection on my bermuda in 8a.

So does doing 2 applications of prodiamine at half the yearly max one in the spring and one at half the yearly max in the fall/winter and doing the same for dithiopyr sound like a good plan?


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## CenlaLowell (Apr 21, 2017)

Theycallmemrr said:


> I am trying to set myself up for a great next season and it was recommended to me to do split pre emergent applications of prodiamine and then dithopyr. That way I can max out on each and get longer protection on my bermuda in 8a.
> 
> So does doing 2 applications of prodiamine at half the yearly max one in the spring and one at half the yearly max in the fall/winter and doing the same for dithiopyr sound like a good plan?


Same mode of action. Use prodiamine and pennant magnum or something like this. Matt has a video on pre emergents it's a good watch


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## WDE46 (Mar 11, 2019)

Can't this type of thing lead to reduced root growth? Does 4 split apps a year not provide you good enough coverage?


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## Jeremy3292 (Apr 30, 2020)

Theycallmemrr said:


> I am trying to set myself up for a great next season and it was recommended to me to do split pre emergent applications of prodiamine and then dithopyr. That way I can max out on each and get longer protection on my bermuda in 8a.
> 
> So does doing 2 applications of prodiamine at half the yearly max one in the spring and one at half the yearly max in the fall/winter and doing the same for dithiopyr sound like a good plan?


I do 4 split apps on my bermuda that equal the max yearly rate at roughly the following times of the year. I am in upstate SC for reference (not too far from you).

Sept 15
Nov 15
March 15
May 15

Roughly 60 days or 8 weeks between apps. This helps provide coverage year round. I also have a poa annua problem in my area so the fall apps are very critical.


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## BermudaBoy (Jun 27, 2019)

Jeremy3292 said:


> Theycallmemrr said:
> 
> 
> > I am trying to set myself up for a great next season and it was recommended to me to do split pre emergent applications of prodiamine and then dithopyr. That way I can max out on each and get longer protection on my bermuda in 8a.
> ...


This used to be my schedule but I loved March and May to February and April due to sporadic unseasonal weather the last couple of years. I used dithiopyr in the fall and prodiamine in the spring and outside of pulling up a random weed here or there, I'm weed free all year. It works so well that my neighbor finally came over and asked how I handle my weed problem.


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## Jeremy3292 (Apr 30, 2020)

BermudaBoy said:


> Jeremy3292 said:
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> > Theycallmemrr said:
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Yes, those dates can vary by a few weeks based upon weather but are a good general guideline for our region. You pretty much can't mess up if you follow those dates.

I prefer dithiopyr in the spring as it has some post emergent effect on young crabgrass should you have missed anything. But again you can't go wrong using prodiamine or dithiopyr. I tend to switch between the two regularly for no other reason than my own peace of mind lol.

I actually just purchased this: https://www.domyown.com/the-anderson-turf-fertilizer-with-426-barricade-p-21360.html

$40 with free shipping after 10% off coupon code. Cheapest I've seen anywhere - 50 lbs bag too.


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## BUbbaSwine (May 8, 2018)

Here comes the stupid question, why stay inside the max recommended application per year?


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## BermudaBoy (Jun 27, 2019)

BUbbaSwine said:


> Here comes the stupid question, why stay inside the max recommended application per year?


Both are root pruners but Prodiamine has a yearly max. Exceeding it can cause root damage and stunt the growth of your established turf.


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## rjw0283 (May 11, 2020)

BUbbaSwine said:


> Here comes the stupid question, why stay inside the max recommended application per year?


I push it, I'm probably over quite a bit for the year in the front. Grass looks great, I also have beach sand for soil, I don't think it stays in the soil as long as regular type soil. I started using more because coverage wasn't lasting very long. 4 apps a year without going over the max yearly rate is probably what I should be doing.


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## BUbbaSwine (May 8, 2018)

That's what I needed to know. I put down Lebanon Turf 0-0-7 .38Prodiamine in the Spring. We were weird with temp swings in March/April, I got it down around Easter. I have noticed over the last couple weeks I'm starting to get weeds popping up, but nothing huge. Probably going to switch to liquid PreM next year and split with dithiopyr and prodiamine in Spring and prodiamine in fall.


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## Jeremy3292 (Apr 30, 2020)

BUbbaSwine said:


> That's what I needed to know. I put down Lebanon Turf 0-0-7 .38Prodiamine in the Spring. We were weird with temp swings in March/April, I got it down around Easter. I have noticed over the last couple weeks I'm starting to get weeds popping up, but nothing huge. Probably going to switch to liquid PreM next year and split with dithiopyr and prodiamine in Spring and prodiamine in fall.


Once you get into August, any pre-m is going to be on its way out regardless. This is why I do 4 split apps a year to extend coverage as long as I can. If you slap down 1/2 the annual max in March, you are risking lots of leaching from heavy rains in April. If you do 1/4 the annual maximum on March 15, May 15, Sept 15, and Nov 15 you get a lot better coverage.


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## DuncanMcDonuts (May 5, 2019)

I've been applying prodiamine at 1/2 rates in February and in October. I also apply dithiopyr at 1/2 rate in June. There are some areas of overlap when the preemergents start to break down. I purchased those two preM from The Lawn Care Nut's suggestions, but after reading more about how they have similar mechanisms, I would've probably bought prodiamine and a different secondary preM. My grass has been growing well, other than this recent dry spout that's causing it to wilt.


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## bwright (Sep 6, 2018)

Jeremy3292 said:


> BUbbaSwine said:
> 
> 
> > That's what I needed to know. I put down Lebanon Turf 0-0-7 .38Prodiamine in the Spring. We were weird with temp swings in March/April, I got it down around Easter. I have noticed over the last couple weeks I'm starting to get weeds popping up, but nothing huge. Probably going to switch to liquid PreM next year and split with dithiopyr and prodiamine in Spring and prodiamine in fall.
> ...


Cant you break Dithiopir into 3 applications? It would take it all the way to maxing out, but still be correct, right?

So:
Sept 1 Prodiamine
October 1 Prodiamine
Feb 1 Dithiopir
March 1 Dithiopir
May 1 Dithiopir


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## Mewwwda (Jul 15, 2020)

DuncanMcDonuts said:


> I've been applying prodiamine at 1/2 rates in February and in October. I also apply dithiopyr at 1/2 rate in June. There are some areas of overlap when the preemergents start to break down. I purchased those two preM from The Lawn Care Nut's suggestions, but after reading more about how they have similar mechanisms, I would've probably bought prodiamine and a different secondary preM. My grass has been growing well, other than this recent dry spout that's causing it to wilt.


So would it be better to use Prodiamine and another PE with a different mechanism? If so, which would most recommend to go along with it?

Seems like most people are using these 2 with good results though?


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## Jeremy3292 (Apr 30, 2020)

bwright said:


> Jeremy3292 said:
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I would not. You may not be putting down enough AI (active ingredient) each time. Would be best to stick with 4 times a year divided by annual max. And just to be clear do not use the annual max of prodiamine AND dithiopyr. It's annual max / 4 not annual max prodiamine + annual max dithiopyr / 4.

Also I see you are in Alabama so I would not use those dates. Putting down pre-m Sept 1 and Feb 1 is wasteful and won't help bc no poa is growing Sept 1 and no summer weed is growing Feb 1 or even March 1 for that matter. Stick with the dates I gave previously. Just monitor the weather patterns.


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## DuncanMcDonuts (May 5, 2019)

Mewwwda said:


> DuncanMcDonuts said:
> 
> 
> > I've been applying prodiamine at 1/2 rates in February and in October. I also apply dithiopyr at 1/2 rate in June. There are some areas of overlap when the preemergents start to break down. I purchased those two preM from The Lawn Care Nut's suggestions, but after reading more about how they have similar mechanisms, I would've probably bought prodiamine and a different secondary preM. My grass has been growing well, other than this recent dry spout that's causing it to wilt.
> ...


It would be ideal to use preemergents with different mechanisms. I haven't done my research but I've heard of pennant magnum and simazine. I have years worth of dithiopyr to get through before replacing my supplemental to prodiamine. Honestly, my turf will probably be dense enough that I'll only need prodiamine by then.


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## CenlaLowell (Apr 21, 2017)

DuncanMcDonuts said:


> Mewwwda said:
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Can never have enough information


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## Theycallmemrr (May 16, 2019)

Jeremy3292 said:


> Theycallmemrr said:
> 
> 
> > I am trying to set myself up for a great next season and it was recommended to me to do split pre emergent applications of prodiamine and then dithopyr. That way I can max out on each and get longer protection on my bermuda in 8a.
> ...


This is what I have planned to do. I was going to do one app of prodiamine (~ 15 Sept) and one of dithopyr (~15 Nov) then an app of prodiamine (~ 15 March) and dithopyr (~15 May) depending on soil temp.


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## Mewwwda (Jul 15, 2020)

So if I had 2 or 3 different pre-emergents, say Prodiamine, Isoxaben, and maybe Simazine, are these more effective at different times of the year against either winter or summer weeds? Or do you just go with what you have?

In my case, I have a really bad case of goosegrass from me tearing up the ground when I seeded. Also have a good bit of spurge. Would these PEs be any more/less effective depending on time of the year?


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## cldrunner (May 14, 2019)

@Mewwwda I am using all three in a few days. I am actually going to use Dithiopyr because I have two WSB's that I need to use. I am using Isoxaben for better broadleaf control as prodiamine and dithiopyr do not cover all the broadleaf's.

I have been very succesful the past two years using Simazine in the Fall for POA. It is so cost effective to use. Basically, $7.00 for two 1/2 quart apps in fall and spring for 20K yard. You have to be careful with Simazine on hybrid bermuda. I use lower rates.

The great thing about those three is they are different mode of actions and cost effective to apply.

Dithyiopyr(grassy and some small seed broadleaf)(k1,3)---- $1.05 per 1000 sq ft
Prodiamine(grassy and some broadleaf)(k1,3)-----$0.30 per 1000 sq ft
Isoxaben(broadleaf)(L,21)------$4.15 per 1000 sq ft
Simazine(grassy and some broadleaf-- mostly used for POA)(c1,5)------$0.17 per 1000 sq ft

My plan looks something like this:

September 1st-7th: 1/2 rate Dithyiopyr(grassy) and 1/2 rate Isoxaben(broadleaf)
September 15th or so: Full rate Simazine(POA +++) 1/2 qt for 20K
February 15th 2021: 1/2 rate Dithyiopyr, 1/2 rate Isoxaben, Full rate simazine(1/2 quart for 20K)


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## Mewwwda (Jul 15, 2020)

@cldrunner I think my plan will look very similar to yours, except I have Prodiamine instead of Dithiopyr. Maybe add that in somewhere down the road. This new hobby is starting to hurt the ol wallet!

I'm looking to purchase some Isoxaben and Simazine, does anyone have some they would like to split up? Maybe go halfsies on Isoxaben?

Also, I'm in North Alabama, what would a rough estimate of my application dates look like?


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## cldrunner (May 14, 2019)

@Mewwwda i think you need to get your Fall Pre emergent down as soon as possible. I am south of you in Texas and shoot for Late August/early September. I am still waiting for my Isoxaben and Simazine but will put down my prodiamine or dithioper in the next few days and the other two later in the week.


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