# Pre and post emergent questions



## kur1j (Jul 2, 2017)

So I have found and read the Bermuda triangle post (Bermuda Triangle) but have a few more in-depth questions.

Pre-emergent questions:

I have a SiteOne that I have been getting my Lesco fertilizer from and they have a schedule to put out Dimension in Sep or Oct and then another application of Pre-M/Stonewall in November/December. Then repeat the process in Jan/Feb (Dimension) and then March/April (Stonewall/Pre-M).

Lesco 25-0-10 .21% Dimension
Lesco 24-0-7 with .43% Stonewall
Lesco 25-2-6 with .86% Pre-M.

1) What is the difference between Dimension/Dithiopyr (looks to be the same), Stonewall, Pre-M, Prodiamine, Tenacity?
2) Do they have any advantage/disadvantages one over the other?
3) Why should I perform one application of one product and an application of another 2 months later? Is it just cross coverage? 
4) Should I follow this schedule of just buying granular? Does it just cost less for the liquid?
5) If I do liquid, should I stay on the same schedule and fertilize as well when I put out the liquid?
6) Should I put out Prodiamine and Dithiopyr of liquid to cross cover is it necessary?
7) With the liquid do I need a surfactant?

Post-emergent questions:

I have a lot of sedge that seems to be popping up and other random stuff. I also have what looks to be some St. Aug in my grass.

I assume that the Celcius would kill the St Aug.?
What do I do with the weeds I have now? Since it is late in the year, should I be putting down the pre-emergence and waiting until next year or should I go ahead and get the Celcius/Certainty and spot spray to kill it now?
Tenacity is also recommended as a post and pre-emergent. Is there an advantage/disadvantage to it (e.g. will it kill something that the others won't)?

What is the differences in the ending of the names in the herbicides?

I have seen 65WG, 4F, 1EC, 40WP, 60DF, 3.8CS

Thanks for the help in advance!


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## Mightyquinn (Jan 31, 2017)

kur1j said:


> So I have found and read the Bermuda triangle post (Bermuda Triangle) but have a few more in-depth questions.
> 
> Pre-emergent questions:
> 
> ...


I'll take a poke at answering this as best I can 

*Pre Emergent*

1) Dimension is just a name brand of Dithiopyr and Stonewall is a name brand of Prodiamine and Pre-M is a brand name of Pendimethalin(Halts uses this too). Tenacity should not be used on bermuda as far as I know.

2) Dimension and Prodiamine are used the most by members here as it has shown to do the best at keep the most weeds at bay and has the longest life in the soil. Pendimethalin has a very short life in the soil so has to be applied more often.

3) By using the same product over and over, the weeds "can" become resistant to the herbicide so switching them up can reduce the chance of this happening. I have not heard of it actually happening to anyone on the forums though.

4) Granular is MORE expensive than spraying the liquid form but depending on how many sq/ft of lawn you have the price may be negligible if you have a very small lawn. Granular is also easier to apply since almost all homeowners have a spreader.

5) If you spray liquid, you can lay fertilizer with it as there shouldn't be any issues but I would lay the fertilizer first so it doesn't stick to the wet grass from spraying the Pre Emergent. As far as the schedule goes, you don't have to stick to the time frame per se or the soil temp recommendations. As long as you are spraying and keeping your barrier intact you will be fine(2 application-6 months apart/3 applications-4 months apart and so on of the yearly max of the product).

6) You can go with one or the other as MANY of us here have only one and have been using it for years with great success.

7) No you do NOT need a surfactant as it needs to be washed down into the soil to be activated with at least a .5" of irrigation or rainfall within 2 weeks of application.

*Post Emergent*

1) No, Celsius is safe for St. Augustine

2) With the weeds you have now, you can still go ahead and kill them with Celsius/Certainty or just live with them and start fresh next year. Me personally, I would kill them as I don't like to have any weed hang around for any longer than it needs to. I guess it also depends on how many weeds we are talking about too. If you just have a few here and there, I wouldn't worry about too much. As for the Pre Emergent, I would go ahead and get a barrier down NOW and make sure you put enough down to carry you through to March/April. It will prevent a lot of the Winter weeds from coming up and looking like crap when the lawn is dormant.

3) Tenacity isn't really used on Warm Season turf, I know it is labeled safe for some varieties of Warm Season turf but it won't really do anything that Celsius and Certainty won't do.

4) Most of those numbers are just the way the herbicide is formulated. WG-wettable granular WP-wettable powder..... I would have to Google the others to find out what they mean 

I hope this help you some, feel free to ask if I didn't explain something good enough. :thumbup:


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## Movingshrub (Jun 12, 2017)

kur1j said:


> So I have found and read the Bermuda triangle post (Bermuda Triangle) but have a few more in-depth questions.
> 
> Pre-emergent questions:
> 
> ...


1. Dimension and Dithiopyr are the same thing - Think Advil vs Ibuprofen.
2. They are very similiar. Dithiopyr has a post emergent impact on very young crabgrass. If you want to know more of the differences, see page 72 of this http://media.clemson.edu/public/turfgrass/2017%20Pest%20Management/2017%20Pest%20Control%20Recommendations.pdf
3. This question has a few ways to slice it.
Some products recommend split application such as dithopyr
Other times you could be trying to broaden the effective band of weeds covered based on what's germinating by time of year. For example, you could put down barricade (prodiamine) in early September to try to prevent poa annua, and then in November, come back with Princep (Simazine) since it has a post emergent impact as well, on any poa annua that got by the prodiamine. Plus, they have different modes of action.

Some plants do build resistance to particular chemicals.

Poa annua is one of them, as well as goosegrass. http://www.tennesseeturfgrassweeds.org/Pages/Herbicide-Resistance.aspx

Some poa annua has developed resistance to glyphosate, simazine, and prodiamine.

4. Liquid costs way less per application.

5. You may not actually want the nitrogen that's in some of those granular versions, especially when applying late summer/early fall. I know Home Depot carries a granular dithopyr and pendimethalin (which can stain) and I think both come in a 0-0-7 version. In my opinion, consider fertilizer and the pre-emergent as separate products. I understand the convenience, especially if doing a summer application but I'd prefer my chemical and nitrogen application not to be connected.

6. Your call. Prodiamine is cheaper and is a dinitroaniline herbicide. Allegedly, the dinitroaniline herbicides can impair root development for non established turf grass. DIthiopyr, when applied correctly, isn't supposed to have the same root pruning effect.

7. Read the product label of whatever you buy. Probably not required if we are talking pre-emergent since it's usually designed to go into the soil rather than be absorbed. Make sure to time application before rain or irrigate accordingly afterward.

Post Emergent:
Celsius is compatible with St. Augustine.

For existing weeds, especially if they are perennials, then yeah smoke them. 
I am in Huntsville as well. You could use 2,4-D/weed b-gon for broadleaf weeds since it's starting to cool down around here, or if you have celsius, by all means use it.

My yard isn't fully established, otherwise I'd be putting down prodiamine now, combined with something like simazine or monument to get any poa annua that's already germinated. Poa annua is already germinating here in Huntsville.

You are going to want a winter pre-em and a fall-em so I'd suggest you put down something this fall. If you're picking between prodiamine or dithiopyr, I'd go with prodiamine.

Here is a break down of the WG, F, etc. http://www.hort.cornell.edu/turf/shortcourse/BacktoBasics.pdf

Don't use Tenacity on your bermuda grass unless you are an Alabama fan. Go vols.


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## kur1j (Jul 2, 2017)

Awesome! Thanks for the reply and answering all of the questions.

I have two follow-up questions if you don't mind. The schedule that SiteOne provided me said to apply the Dimension in Sept/Oct and then either Stonewall/Pre-M in Nov/Dec. Repeat that process over (Dimension)Jan/Feb and (Stonewall/Pre-M)March/April. But you are saying to only use it every 6 months or every 4 months? Pre-Em is only useful going into fall and right before the Bermuda wakes up in the spring I thought simply to keep the weeds from germinating?

As for the Post Emergent...I want to kill the St Augustine haha. I assume it was just in the sod and it is sticking around. I've heard quinclorac will kill it in bermuda.

There aren't a massive number of weeds but there is a lot of nutsedge in certain areas because we have been getting a lot of rain.


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## Mightyquinn (Jan 31, 2017)

kur1j said:


> Awesome! Thanks for the reply and answering all of the questions.
> 
> I have two follow-up questions if you don't mind. The schedule that SiteOne provided me said to apply the Dimension in Sept/Oct and then either Stonewall/Pre-M in Nov/Dec. Repeat that process over (Dimension)Jan/Feb and (Stonewall/Pre-M)March/April. But you are saying to only use it every 6 months or every 4 months? Pre-Em is only useful going into fall and right before the Bermuda wakes up in the spring I thought simply to keep the weeds from germinating?
> 
> ...


For warm season grasses Spring and Fall/Winter are the prime time for weeds as the lawns are either waking up or going to sleep so weeds can be more invasive at these time which is why they recommend applying it at these times. If you are consistent with your Dimension/Prodiamine applications these "dates" become irrelevant since you will always have a barrier down to prevent the weeds from germinating. You will need to look at the label on whichever product you decide on and see what the yearly MAX rate is and then divide that into how many applications you are wanting to apply so you have year long control of the weeds. Weeds can still germinate in the Summer while the bermuda is growing but is less likely since a healthy stand of bermuda will choke most of them out.

I would just concentrate on killing the SA and nutsedge right now. I know SA is very sensitive to a lot of chemicals but depending on how much you have, I would just hand pull it and let the bermuda take it over. What is your HOC on your bermuda?


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## Movingshrub (Jun 12, 2017)

Wouldn't katana or monument hurt both the st aug and go after the sedges?


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## kur1j (Jul 2, 2017)

Yall are answering too fast and I can't respond fast enough! haha.



> 3. This question has a few ways to slice it.
> Some products recommend split application such as dithopyr
> Other times you could be trying to broaden the effective band of weeds covered based on what's germinating by time of year. For example, you could put down barricade (prodiamine) in early September to try to prevent poa annua, and then in November, come back with Princep (Simazine) since it has a post emergent impact as well, on any poa annua that got by the prodiamine. Plus, they have different modes of action.


So from the sounds of it, it is mainly to spread the coverage around where one might not be good at keeping a particular weed at bay and the other will handle it.

What combo of pre-emergent would you suggest to put down? It sounds like Prodiamine is a pre-emergent that you put down throughout the year and not just in the fall and spring?



> 5. You may not actually want the nitrogen that's in some of those granular versions, especially when applying late summer/early fall. I know Home Depot carries a granular dithopyr and pendimethalin (which can stain) and I think both come in a 0-0-7 version. In my opinion, consider fertilizer and the pre-emergent as separate products. I understand the convenience, especially if doing a summer application but I'd prefer my chemical and nitrogen application not to be connected.


I'm completely okay with putting down liquid and the fertilizer separate. Seems cheaper in the long run and gives a little more options. But sacrifices convenience.



> 6. Your call. Prodiamine is cheaper and is a dinitroaniline herbicide. Allegedly, the dinitroaniline herbicides can impair root development for non established turf grass. DIthiopyr, when applied correctly, isn't supposed to have the same root pruning effect.


My lawn has been sodded for about a year now. Would that cause any problems going forward with Prodiamine? I'm not sure what a dinitroaniline herbicide is or what makes it different than others. What makes it different?

If you are recommending Prodiamine (given that you think a year of growth would be fine), I'll probably go with that and one of the other suggestions that you mentioned of Simazine or Monument. Is there a difference between the two?



> For warm season grasses Spring and Fall/Winter are the prime time for weeds as the lawns are either waking up or going to sleep so weeds can be more invasive at these time which is why they recommend applying it at these times. If you are consistent with your Dimension/Prodiamine applications these "dates" become irrelevant since you will always have a barrier down to prevent the weeds from germinating. You will need to look at the label on whichever product you decide on and see what the yearly MAX rate is and then divide that into how many applications you are wanting to apply so you have year long control of the weeds. Weeds can still germinate in the Summer while the bermuda is growing but is less likely since a healthy stand of bermuda will choke most of them out.
> 
> I would just concentrate on killing the SA and nutsedge right now. I know SA is very sensitive to a lot of chemicals but depending on how much you have, I would just hand pull it and let the bermuda take it over. What is your HOC on your bermuda?


Is Prodiamine/Dimension something that "sticks" around all year long? From the way you talk, it sounds like it? Making this something you just put down on a schedule once a quarter? I was under the impression that pre-emerg was only useful during Fall (oct/nov) and then winter (dec/jan) and then spring (march/april)?

Yeah, I'm wanting to kill the nutsedge so I'm planning on getting some of the Certainty to try and get rid of it. As for the SA, there is a decent amount, I tried picking at it but couldn't really get it up.

I mowed at ~.9" for about 1 month or so after I scalped at .75". I chickened out and didn't want to cut lower because I was scared it was too late in the season, and for second I didn't know what I was doing and didn't want to kill it. I damaged the mower and I'm working on reparing it and currently mowing at ~1.25 to 1.5" at the moment. My plan early next year is to scalp down to 3/8" or so and then maintain around .75".



> Wouldn't katana or monument hurt both the st aug and go after the sedges?


I've heard quinclorac would kill the st. aug post emergent. I thought Katana and Monument were both pre-emergent?


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## Movingshrub (Jun 12, 2017)

Katana and monument are post emergents. However, monument lingers and has a pre emergent type of effect on poa annua. Unsure if it does the same for sedges.

I'll response to the rest tomorrow.


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## Movingshrub (Jun 12, 2017)

kur1j said:


> Yall are answering too fast and I can't respond fast enough! haha.
> 
> 
> 
> ...


If your Bermuda sod is well rooted, I would think you'd be fine with Prodiamine. Contact the sod farm and ask them if you are concerned and see what they suggest.

If you want to read about Dinitroanilines, http://agron-www.agron.iastate.edu/~weeds/Ag317-99/manage/herbicide/dnas.html

I have not used any of these methods personally. This is just based off reading the labels.
If you've got a bunch of St Aug, it sounds like quinclorac would be your cheapest choice since the label says not to apply it to St Aug.
If you've got a lot of sedges, you may want to consider Katana. Reading the label, it says St Aug is intolerant.
Reading the label for Monument, it says it will cause reduced growth rate and discoloration to St Aug.
If you don't have much, you may be better off just pulling it and then using Certainty for your sedges.

My FIL, also in Huntsville, asked me to come up with his poa annua control plan for this winter. We are applying Barricade (prodiamine), Princep 4L (simazine), and Monument 75WG.

I had asked the experts at UGA what they suggested for my newly sprigged TifTuf lawn that's still filling in. They suggested simazine and Monument for the first year then next winter I plan on applying the above plan. I was going to use simazine and monument no matter what since simazine is dirt cheap $60 for 2.5 gallons and I wanted to give my yard the best chance going into next spring.

This plan is the Syngenta Poa Annua assurance plan. https://www.greencastonline.com/greentrust365/golf_pdfs/2018-poa-annua-assurance-program-non-overseeded-fairways.pdf

Also, you have got other options than Site One. The Madison County co-op on the north end of town carries Anderson products and a good selection of herbicides. They will order stuff too if they don't have it in stock. Plus there is also CT Garvins.


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## kur1j (Jul 2, 2017)

Thanks again.

For the preemergent I'm going to follow your recommendation of using the Prodiamine and the Princep. Will probably order those this weekend.

Hopefully not to sound ignorant for missing it, but I'm still not quite sure of when to actually apply. Can you help me understand the timing a little better of when to apply the preemergent? I get the general idea of fall (sept/oct), winter(dec/jan), spring (march/april). But the way people are taking is that prodiamine just had to be applied on a schedule? e.g. every 4 months and not to exceed the yearly rate, so that means if I apply it now Oct 1st i would apply more Feb 1st and then again June 1st? Repeat again in Oct. Is that correct? Does the labels say how long they should last? For example is the samizine or dimension long lasting like the prodiamine or shorter like PreM?

I did some looking for the shelf life of some of these products but couldn't find much. How many years will this stuff last? For example the smallest container of the Princep 4L is like 2.5 Gallons. At the max rate for the size of my lawn 1.5oz per 1ksqft I would have enough to do 35 applications and with 2 applications a year it would last me almost 18 years.

It also looks like the Monument is a post emergent. Is there a reason why you wouldn't be using Celsius and Certainty? Is it just tochsve have additional chemicals?


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## Movingshrub (Jun 12, 2017)

kur1j said:


> For the preemergent I'm going to follow your recommendation of using the Prodiamine and the Princep. Will probably order those this weekend.


What did you end up going with?



kur1j said:


> Hopefully not to sound ignorant for missing it, but I'm still not quite sure of when to actually apply. Can you help me understand the timing a little better of when to apply the preemergent? I get the general idea of fall (sept/oct), winter(dec/jan), spring (march/april). But the way people are taking is that prodiamine just had to be applied on a schedule? e.g. every 4 months and not to exceed the yearly rate, so that means if I apply it now Oct 1st i would apply more Feb 1st and then again June 1st? Repeat again in Oct. Is that correct? Does the labels say how long they should last? For example is the samizine or dimension long lasting like the prodiamine or shorter like PreM?


The timing is driven by local ground temperature, how long the product lasts, and whether your plan includes just a pre-em, or any kind of post-em as well.

I applied Barricade (prodiamine) and Princep 4L (simazine) a few days before Halloween. I am going to apply Monument this week. I would have liked to have applied them all the same day, but I simply didn't have time. Furthermore, as a fellow Huntsvillian, I am sure you will recall the weekend being kind of cold and rainy.

From what I gather, it seems many people do two applications of pre-em a year (assumuming prodiamine, dithiopyr, or pendamethalin), with one in the fall and another in the spring. If you were to apply really low amounts of product, then sure you could be applying once a month, if you apply a higher amount, you would apply less often; it just depends on the product. Prodiamine, according to the label, could last eight months if applied at 1.50lb/acre, depending on the environmental conditions.

I don't think any simazine application is going to last 8 months. It's my first year using simazine; I think it's typically applied once in the fall/winter, and potentially there is a follow-up application in late winter before early spring green-up, but I'm not certain on that one.



kur1j said:


> I did some looking for the shelf life of some of these products but couldn't find much. How many years will this stuff last? For example the smallest container of the Princep 4L is like 2.5 Gallons. At the max rate for the size of my lawn 1.5oz per 1ksqft I would have enough to do 35 applications and with 2 applications a year it would last me almost 18 years.


Contact the manuf for that question My guess is 3-5 years, if stored in a cool, dark, and dry environment. You may want to consider splitting or sharing among two other peoeple in Huntsville. Prodiamine and simazine are cheap. It was the cost of ordering monument that led me to split all three products with my father-in-law.



kur1j said:


> It also looks like the Monument is a post emergent. Is there a reason why you wouldn't be using Celsius and Certainty? Is it just tochsve have additional chemicals?


Celisus doesn't have poa annua listed on its label as a controlled plant, and Certainty isn't as effective at control of poa annua as Monument. There's a reason I

This is where I turned to for advice on bluegrass control; Annual Bluegrass Control Programs for Georgia Lawns - https://secure.caes.uga.edu/extension/publications/files/pdf/B%201463_2.PDF

My plan uses Group 2 (Sulfonylureas, such as Monument, Katana, and Revolver), Group 3 (Such as Prodiamine), and group 5 (such as Simazine) herbicides, hopefully to help prevent escapes and discourage resistance.



kur1j said:


> For the preemergent I'm going to follow your recommendation of using the Prodiamine and the Princep. Will probably order those this weekend.


With that all being said, what herbicides did you apply and what is your plan going forward?


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## kur1j (Jul 2, 2017)

Movingshrub said:


> kur1j said:
> 
> 
> > For the preemergent I'm going to follow your recommendation of using the Prodiamine and the Princep. Will probably order those this weekend.
> ...


Thanks. So i ended up doing a lot more research into all of this and ended up with more checmicsls that I probably should have haha.

But for preemergent I went with princep and prodiamine. Put both out around Oct 10th. A few days later I went and used Celsius and dismiss to kill off my broadleaf and nutsedge and other various weeds. Seems to have worked really well.

I also ended up getting some monument (but only the 20$ pack) and MSMA to kill off some dallisgrass. If you need some let me know.

At this point I have enough chemicals to treat a small farm. If a weed can live through all of these chemicals it deserves to live. The only challenge I have right now is figuring out how to get rid of what I believe is zoysia is a few areas of my yard. Seems like the only way to kill it is to glyphosate it which will kill the bermuda as well unfortunately.


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## Movingshrub (Jun 12, 2017)

Understoood.

I've got a jug of prodiamine, princep, the 5x5g box of monument, a bottle of Celsius, Certainity, some blue tracker dye, NIS surfactant, a jug of glyphosate, and a stray bottle of weed-b-gon.

In lieu of using using MSMA, I just hand brush anything that looks like crab, goose, or dallisgrass with glyphosate.

The only other item I am considering is either a MSO to mix with Celsius, or a three way herbicide, that is 2,4-d ester based instead of amine based, to control winter annuals. I want to see how the princep, monument, and Celsius do on the winter weeds before buying anything else.

The other piece of this is size of the yard. My yard is 13,000 sqft and my FIL's is 26,000, so combined we are almost treating an acre. If my math is right, you're cutting an area smaller than the 18 yard penalty area on a soccer field.

Anyways, you should be covered for years to come! Good luck on the zoysia removal in the Bermuda; the only route I know of is to use glyphosate.


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