[SmartLawnCare]

I am in the third season of Tenacity use and find it an excellent product for bent grass control. I use the label rate and spray 1 gallon/1000 sqft. Tall fescue does bleach out some, but the only time I've had a problem was because the customer was overreacting. No comeback so far, will wait until the 3rd year after treatment to give a full seal of approval.

First app you don't see much, second app and it will really start to bleach out. Third app and you will be spraying mostly white turf with bits of green in it. It is very slow acting on bent. Make three apps 10 to 14 days apart. Expect it to be a multiple year process.

Not sure why he mentioned multiple year process?

My concern started when inspecting the results of treatments in the spring. All lawns went through the 3x Tenacity spray followed by slice seeding with top quality KBG/PRG blend. The treated lawns were clear of bent, but Poa trivialis was showing up in its place. I honestly did not see any signs of Poa triv during the initial assessments. The spots were where the bent grass was extremely heavy, constantly moist soil (low areas of the lawn). Of course the customer thought the bent grass was not killed. Most of them don't want to go through another treatment, it galls me!

I did notice one lawn treated for bent 3x and we didn't seed it immediately due to weather conditions. Next week, we saw the Poa triv, did a RoundUp treatment and seeded a week after. It is perfect, no sign of either weedy grass.

Anyone else go through this?

 

[ron mexico75]

I am in the third season of Tenacity use and find it an excellent product for bent grass control. I use the label rate and spray 1 gallon/1000 sqft. Tall fescue does bleach out some, but the only time I've had a problem was because the customer was overreacting. No comeback so far, will wait until the 3rd year after treatment to give a full seal of approval.

Not sure why he mentioned multiple year process?

My concern started when inspecting the results of treatments in the spring. All lawns went through the 3x Tenacity spray followed by slice seeding with top quality KBG/PRG blend. The treated lawns were clear of bent, but Poa trivialis was showing up in its place. I honestly did not see any signs of Poa triv during the initial assessments. The spots were where the bent grass was extremely heavy, constantly moist soil (low areas of the lawn). Of course the customer thought the bent grass was not killed. Most of them don't want to go through another treatment, it galls me!

I did notice one lawn treated for bent 3x and we didn't seed it immediately due to weather conditions. Next week, we saw the Poa triv, did a RoundUp treatment and seeded a week after. It is perfect, no sign of either weedy grass.

Anyone else go through this?

Thank you for posting your experience. I can say that the fescue is recovering very noticeably. I haven't taken any new pics but I'll update this thread soon. I did apply some granular iron (9 or 10%) just because I happened to have some, I figured it can't hurt.

I have noticed also that the bent is white and turning brown too. I still plan on doing the 2nd and 3rd app. However, I think it looks worse after the 1st app because I ended up spraying 2 g per 1000 due to walking too slow.

 

[Puttinggreens]

One thing I have found is that spring apps of Tenacity are hard on most of the desirable grasses. After trying to eliminate bent on just a handful of lawns in two different springs I'm done. Too much of a set back. July, Aug Sept are ideal for us.

 

[SmartLawnCare]

One thing I have found is that spring apps of Tenacity are hard on most of the desirable grasses. After trying to eliminate bent on just a handful of lawns in two different springs I'm done. Too much of a set back. July, Aug Sept are ideal for us.

I have used Tenacity in the spring. It worked out the same as fall treatments. On one yard, the bentgrass died out and the KBG took over right away, no seeding needed. Maybe it was too strong or weather wasn't the best for you.

 

[ron mexico75]

One thing I have found is that spring apps of Tenacity are hard on most of the desirable grasses. After trying to eliminate bent on just a handful of lawns in two different springs I'm done. Too much of a set back. July, Aug Sept are ideal for us.

hey puttinggreens, you were right, the fescue is recovering. Slowly, but I can tell it's rebounding. I'm due for the 2nd round this Fri or Sat since its been 3 weeks. I'm just going on top of and around the bent patches. No blanket spray this time. All of the bent is white so I can see where the stolons extend beyond the mats. I will spray out and around each patch.

 

[ron mexico75]

well, here are some updated pics for anyone following. You can see in the first pic that the fescue has covered remarkably. Thanks to those who gave me encouragement. You can tell by the earlier pics I thought I killed the entire 13,000 sq ft. The rest of the fescue looks just as good. I think the iron I applied about a week or so ago has helped too.

As for the other pics, you can see in some what the bentgrass looks like now after the 2nd app. I will apply the 3rd and final 3 weeks from now and then aerate and seed the following day. Some of the other pics are after I sprayed the 2nd app with the blue turf marker. You can really see how spread out this stuff is. Thankfully I received good advice on this site and blanket sprayed the first app rather than spot. Real hard to see exactly how far out it was spread.

 

[foreplease]

Nice work!

 

[ron mexico75]

Nice work!

Much thanks, I feel a lot better today than I did 2 weeks ago.

 

[countryclublawnllc]

Ron,

I just did a first app on some homeowners association properties last Friday. Will be going 4 sprays at 4 oz./Acre every 7-10 days. Closer intervals will give much better results if you can get back to the properties that soon. Bentgrass at that height is very resilient!

John

 

[ron mexico75]

Ron,

I just did a first app on some homeowners association properties last Friday. Will be going 4 sprays at 4 oz./Acre every 7-10 days. Closer intervals will give much better results if you can get back to the properties that soon. Bentgrass at that height is very resilient!

John

You know, I think you're definitely right. I was cutting yesterday and some of those patches in my pics were starting to green up again. I was just thinking to myself yesterday that I need to do a follow up this Friday which will be 7 days from the 2nd app I did last week.

I had planned 3 apps at 3 week intervals. But, that was for blanket apps and the timing was to let the desirable fescue recover some. Seeing that the first blanket app really showed me where all the bent was, I think I will do 2 more apps both at the 7-10 day interval since they will be spot sprays and not blanket apps.

Since I'm cutting the fescue close to 3.75, you are so right. That bentgrass is like the fullest, thickest mat of hair you'd ever see! It's hurting but seeing some of that green in it yesterday has prompted me to do closer intervals and an extra 4th app.

 

[ron mexico75]

Well here it is 7 days after treatment #2. The bentgrass is really hurting. Most of it is brown/tan but a few of the larger patches had a little green in them.

I'm wondering since some of those mats were so thick and big if I should put some soil over the dead area when I aerate and over seed? Also, you can really see in the pics that I took yesterday that the fescue in the immediate vicinity of the bentgrass patches really lightens up. This time I walked briskly over the patches and did not saturate them like the first time. However, the fescue really seems to be affected by the Tenacity although its only temporary.

I know puttinggreens said he has done many lawns with the same type of after effect on the fescue. I always thought that the fescue would be totally unaffected. Both apps now, the one where I walked too slow and the most recent where I walked briskly and didn't saturate, still show that bright kind of lime green color on the fescue. It is temporary but I'm wondering if fescue always turns this light color?

Anyways, these pics are at 28 days total since the first app. They are also 7 days after the second app.

 

[RodneyK]

Interesting, seems more brown than white especially after two apps. I previously said multiple years only because it is hard to spray every little piece of it. If you are good and get it all the first time then more power to you!

 

[ron mexico75]

Interesting, seems more brown than white especially after two apps. I previously said multiple years only because it is hard to spray every little piece of it. If you are good and get it all the first time then more power to you!

yeah exactly right. Almost all of it is brown, I mean dead brown. There are some areas that have white tips around the side in the big open area. I didn't take pics of that area with the most recent post.

I can note this due to observation, it seems to me that the bentgrass that's in the shade/less sunny areas, still has white tips and is much slower to die off. The areas in full sun appeared to have died (brown) after 2 apps. I'm still planning to do a third and final next week and will aerate and over seed the following day.

Like I stated before, I asked the question but I've had time to think now, I am going to aerate/seed and then spread compost over the areas of dead bentgrass. I want the fescue to come in nice and thick where all those dead mats are at now.

 

[Puttinggreens]

Looks good!

 

[ron mexico75]

Looks good!

Thanks! Thanks for the help and reassurance too throughout this thread.

 

[countryclublawnllc]

This is on Monday, right before second application, 10 days after 4 oz/Acre was applied. .5 H20/1000 with a spreader. Looks to be working pretty well.

 

[ron mexico75]

This is on Monday, right before second application, 10 days after 4 oz/Acre was applied. .5 H20/1000 with a spreader. Looks to be working pretty well.

That is wild looking. Mine never looked that bright white after application. You can go back and look through my pics especially on page 3 after the 1st app.

I also see that the fescue looks all dark green and you don't have any of that real bright green/yellowing like I got. I wonder why?

 

[countryclublawnllc]

It is virtually all kentucky blue perennial mix. Some other areas of shade had some fescue that was just a little off. Hardly even noticeable though. I will post more next week before third app.

 

[ron mexico75]

It is virtually all kentucky blue perennial mix. Some other areas of shade had some fescue that was just a little off. Hardly even noticeable though. I will post more next week before third app.

Oh ok, maybe that's why. Maybe the blue grass is more tolerable of the AI than tall fescue is.

Not sure if I need to do the 3rd app because the stuff looks like toast. However, I'm going to do it anyways because I like sticking to the plan.

 

[ron mexico75]

smic451, why the Prodiamine? You must not be planning to overseed any of it? Cool that you are seeing results. Tenacity and Quinclorac both show damage quickly.

Ron, good goings you are going to be prime time with seed and topdress plan.

For sure foreplease. Can't wait to get this lawn looking good. Tired of looking at dead patches and bright areas of fescue for 2 months.

I'll keep posting pics.
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