Fall pre-m

[hmartin]

How many people that are treating non-irrigated warm season lawns use a pre-emerge in late summer? I was planning on using .5 AI of Barricade around Sept. 1, but it has not rained here in 6 weeks. If this dry spell continues, I think it will just be a waste. Not many of my customers are going to ensure 1/2" of water across there whole lawn to water in the herbicide. I may just save some money and just apply some potash and leave out the barricade.
I am planning on using Simazine/3way in my last round in November. Does anyone care sharing their next to last warm season application.

[LLandscaping]

We apply Lesco Pre-M about the middle of August. We only treat Zyosia and Bermuda lawns.

[ThreeWide]

Just about ready to start doing the same thing in my area.

Don't be concerned about the non-irrigated sites. Barricade can go up to 21 days before being watered in without losing any efficacy. It has a longer half-life than most commonly used preemergents.

[LawnDawg65]

I use simazine in the fall here, it is extremely dry here so I will also apply potash this year along with 3 way. Just curious why you use Barricade or pendamethlin in the fall? I use those products in the spring only for crabgrass prevention, Simazine in the fall is cheap and an excellent product, but this is for Texas= mainly bermuda & St. aug. That's just my opinion but it has seved me well for 21 years, on and I prefer dimension in the spring. Thanks, chris
Texas Dept. Of Agriculture # 0400163

[LawnDawg65]

How many people that are treating non-irrigated warm season lawns use a pre-emerge in late summer? I was planning on using .5 AI of Barricade around Sept. 1, but it has not rained here in 6 weeks. If this dry spell continues, I think it will just be a waste. Not many of my customers are going to ensure 1/2" of water across there whole lawn to water in the herbicide. I may just save some money and just apply some potash and leave out the barricade.
I am planning on using Simazine/3way in my last round in November. Does anyone care sharing their next to last warm season application.

It is not so much the pre-m you have to worry about damaging the grass as it is the broadleaf weed control! be very careful of the dry lawns with no rain in the forecast- because it will "fry a lawn in a heartbeat"

[ThreeWide]

I apply Preemergent in the late Summer to help prevent Poa Annua. Poa has been shown to start germinating as early as August.

In November, I spray Simazine which will knock out any small Poa that might have germinated as well as prevent further germination into Winter. Simazine is not very effective on mature Poa, so this is the reason for the Barricade now.

Poa germinates in a very broad time window here, so you have to protect warm season grasses against it for several months.

This may not be the answer for everyone. It involves how much preemergent you applied in the Spring. If you applied at the max rate in the Spring or late Winter, this app might not be needed at all. In my case, Barricade was applied at 1 lb AI/Acre earlier this year. This is not enough to last well into Fall, which is why another app is needed now. Yes I could have went at 1.5 lb AI/Acre, but chose not to for other reasons.

[LawnDawg65]

I apply Preemergent in the late Summer to help prevent Poa Annua. Poa has been shown to start germinating as early as August.

In November, I spray Simazine which will knock out any small Poa that might have germinated as well as prevent further germination into Winter. Simazine is not very effective on mature Poa, so this is the reason for the Barricade now.

Poa germinates in a very broad time window here, so you have to protect warm season grasses against it for several months.

This may not be the answer for everyone. It involves how much preemergent you applied in the Spring. If you applied at the max rate in the Spring or late Winter, this app might not be needed at all. In my case, Barricade was applied at 1 lb AI/Acre earlier this year. This is not enough to last well into Fall, which is why another app is needed now. Yes I could have went at 1.5 lb AI/Acre, but chose not to for other reasons.

Not so much a big problem here, pretty much the same rates apply here- I go heavy in the fall and lighter in the Spring, I do 7 applications here 3 prem's, 1 fall- 2 spring and 4 dry- 5 apps on HOA'S and Commercial- How many do you do in Georgia? oh I am not a fan of Atrazine but it works better on existing poa, than simazine----- Revolver is the best

[hmartin]

Not so much a big problem here, pretty much the same rates apply here- I go heavy in the fall and lighter in the Spring, I do 7 applications here 3 prem's, 1 fall- 2 spring and 4 dry- 5 apps on HOA'S and Commercial- How many do you do in Georgia? oh I am not a fan of Atrazine but it works better on existing poa, than simazine----- Revolver is the best
LawnDawg, what is the heavier and lighter you are talking about--Atrazine?

Last year I made the mistake of applying Simazine on some lawns that were not dormant yet. Needless to say they were about 2 days later. All brown, no permanent damage, just looked like winter in September.

[LawnDawg65]

LawnDawg, what is the heavier and lighter you are talking about--Atrazine?

Last year I made the mistake of applying Simazine on some lawns that were not dormant yet. Needless to say they were about 2 days later. All brown, no permanent damage, just looked like winter in September.

the heavy I was referring to is the AI in the mix, of course this all depends on the weather around here-ie- dry,wet, cold,warm, this all changes how I mix my tanks, 2 Lesco 300 gallon agitated polly tanks. I have never seen Simazine turn a lawn brown here, some companies, Trugreen will start spraying later this month and it is still 100 + every day, me I will wait a tad longer

[quiet]

Hmmm. Thought provoking.

But I still use pretty much the same thinking as Turf Unlimited. My two 1/2 rate apps of Barricade - 1st one around Labor Day, and 2nd around December 1 - have done just an excellent job all through the year. No poa (except for 1 BIG account), and so little crab grass breakthrough through the year it's not worth mentioning.

But I'm always wary. We're into the 20th month of a now severe drought. All my properties are irrigated, so I can't help hmartin with the current dry conditions . . . Yet I'm sure the weather in MS can turn on a dime! And you'll need 2 weeks for the pre-m barrier to set up! Discuss it with your customers. They'll appreciate it.

Me? I'd put it down to stop the poa. Winter broadleafs are nothing to kill, but poa is a PITA if you miss it . . . Are they (and you) willing to live with poa until next Memorial Day? That one BIG account I mentioned wasn't!

[hmartin]

the heavy I was referring to is the AI in the mix, of course this all depends on the weather around here-ie- dry,wet, cold,warm, this all changes how I mix my tanks, 2 Lesco 300 gallon agitated polly tanks. I have never seen Simazine turn a lawn brown here, some companies, Trugreen will start spraying later this month and it is still 100 + every day, me I will wait a tad longer
I understood that heavier ment more AI. I did not understand or maybe you didn't say what it was you used. Atrazine, Simazine or other?

[hmartin]

Is trugreen spraying Simazine at 100 degrees? The lawns I mentioned earlier were already drought stressed. I think the Simazine put them over the edge.
Lawndawg, You don't think that Simazine will overly stress bermuda in late Summer? I may have to try it again in my lawn just to see if the browning happens again.

[ThreeWide]

If I am not mistaken, the label on Simazine says it should be used after October 1. That said, I still like to wait until we've had a good hard frost or two before spraying. If your Bermuda is green, Simazine will zap the color out of it. It is a very cheap and effective preemergent/postemergent for warm season turf, but it can only be used during the dormant period.

Quiet, that Barricade program might work in your area but probably not in my zone. This is typically a wetter climate than Texas, so 1/2 rate of Barricade applied in December probably would not hold through the following Summer. The issue would be how much product retained during the Winter months while the microbes are inactive. Even with a February application, I have to use a 3/4 rate.

[Threxx]

Can somebody please explain what potash has to do with pre-emergent or do you just happen to apply it at the same time as pre-emergent to 'kill two birds with one stone'?

Also, I have princep (simazine) for use for fall pre-emergent. I live in the Memphis TN area just 10 miles north of the Mississippi border. My lawn is very well watered - it gets a good 40 minutes of watering in all zones 3 times a week (I'm hoping to reduce to 2 times eventually but I just put some zoysia down this year so the roots aren't very deep) - it's completely green and hydrated.

So anyway - for a zoysia lawn in my area that is well watered, is princep/simazine all I need to apply? And if so, when should I apply? I was under the impression I should wait until maybe late September or so... but some of you guys are talking about more or less right about now.

I'm also about to put down some high potash fertalizer (15-0-29) - not sure if I should do that at the same time or if it really matters?

[ThreeWide]

Potash has nothing to do with preemergent fundamentally. Warm season grasses are normally loaded up with Potash as you get closer to the dormant season. It is often convenient to apply K and preemergent at the same time.

For established lawns, applying Barricade or Penimethalin in late August and then following in November with Simazine is a good plan. This is just my opinon, but if it were my new Zoysia lawn I would not apply Simazine or any other commonly used preemergent for that matter during the first year. Those products are harsh on new turf. Even if you did use the Simazine, don't do so until after the first good frost.

Since your Zoysia has a very immature root system, what you need is a preemergent that does not root prune. There is only one such product, but it is not labeled for residential lawns. What you do to your lawn is your own business I suppose. Your BWI rep can probably fill you in on the details I purposely left out.

[LawnDawg65]

If I am not mistaken, the label on Simazine says it should be used after October 1. That said, I still like to wait until we've had a good hard frost or two before spraying. If your Bermuda is green, Simazine will zap the color out of it. It is a very cheap and effective preemergent/postemergent for warm season turf, but it can only be used during the dormant period.

Quiet, that Barricade program might work in your area but probably not in my zone. This is typically a wetter climate than Texas, so 1/2 rate of Barricade applied in December probably would not hold through the following Summer. The issue would be how much product retained during the Winter months while the microbes are inactive. Even with a February application, I have to use a 3/4 rate.

Label states after Sept. 1st on bermuda, and it will in NO WAY brown out the grass, this is Dallas area, yours may be diffrent. Been doing this for 21 years in this area, so this is the only zone I am familiar with. Here no one sprays barricade in the fall -- all simazine, me once others twice.
I do a 7 step program here that works very well/ 2 spring pre-emergents, starting Jan 10th 1st one simazine, 2nd with dimension, then 4 dry apps, mainly 28-3-10 50% scu 4%iron, then weather permitting simazine starting around Oct.15th. thats just the program that works best for me, I treat only the lawns that we mow- around 600 residential, 12 HOA's and 21 commercial properties.Again I am just trying to help, barricade is way too expensive and not as good in the fall as simazine IN THIS AREA.

[ThreeWide]

Label states after Sept. 1st on bermuda, and it will in NO WAY brown out the grass, this is Dallas area, yours may be diffrent. Been doing this for 21 years in this area, so this is the only zone I am familiar with. Here no one sprays barricade in the fall -- all simazine, me once others twice.
I do a 7 step program here that works very well/ 2 spring pre-emergents, starting Jan 10th 1st one simazine, 2nd with dimension, then 4 dry apps, mainly 28-3-10 50% scu 4%iron, then weather permitting simazine starting around Oct.15th. thats just the program that works best for me, I treat only the lawns that we mow- around 600 residential, 12 HOA's and 21 commercial properties.Again I am just trying to help, barricade is way too expensive and not as good in the fall as simazine IN THIS AREA.

Yes you are correct on the date. The Oct 1 date was specifically about Poa Annua.

The label also says that temporary slowing of growth and yellowing of Bermudagrass may occur. That is the reason I've avoided using it active Bermuda.

[Threxx]

Hey guys, I talked to my local BWI rep and described what you were 'alluding' to as a pre-emergent that will not root prune and he told me the name of it (I've forgotten by now) but also told me that he can't sell that to me, even for my own personal use at my home.

He suggested 'dimension' as an alternative to simazine/princep. He said it will not root prune and is very effective. He almost alluded to it being better than simazine is anyway, with the added benefit of not harming my new grass installation.

What do y'all think of using dimension now and then simazine after the first frost and complete dormancy? Or should I just do one of the two or neither?

[quiet]

I'd do neither. You really don't wanna put a pre-m on new sod during the first year. Get those roots established! Dimension will inhibit rooting.

I'm still under the impression that most sod is treated with Siduron (pre-m) at the sod farm and there's really no need to apply during the first year anyway. Fertilize and water the zoysia, and it gets thick and dense enough on it's own to choke out weeds.

[hmartin]

I would use Simazine after the turf goes dormant. Simazine is a photosynthetic inhibitor, not a root inhibitor. If you are still leary, just wait to see how many weeds you actually have. Simazine kills post emerge on many of the same weeds as it does pre-emerge. If you don't have to many weeds, don't spray anything.
I can't understand why the BWI guy would not sell you Ronstar. I did not think that it was restricted use. Maybe TN looks at things differently than MS.

[Terra-Scapes]

Would an application of Simazine, after Oct. 1 or the first frost, harm a hydro seeded Bermuda that was put down in mid August? If so, what Pre-emergent would be sufficient?

This turf is located in Atlanta, Georgia.