# Tenacity Blanket App for PreM Questions



## MarkAguglia (Jul 13, 2017)

I'm considering doing a blanket app of Tenacity as my pre-emergent this year.

When should I start? Is it still the same process as any other PreM? (50+ soil temp/forsythia)My current soil temp is 38 degrees checked at 8am, still frost on the ground.

Do I do one app or multiple apps?

Reasons I'm thinking of using it are:
1. Already have it ($)
2. I have a bentgrass problem
3. I always get a ton of dandelions in spring and this is the only PreM I've seen that may prevent them
4. I have a smaller lawn (4k sqft)

Id like to get it down as soon as I can only because I don't want a white lawn all of May but the weather is not cooperating and I don't see my area hitting 50 degree soil temps for at least another 3 weeks based on the forecast.

I'm still new to the hobby so any help is much appreciated!


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## jessehurlburt (Oct 18, 2017)

I'm new too- I'll let others comment on your plan. I thought I read somewhere that bentgrass should be targeted in the summer though.


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## MarkAguglia (Jul 13, 2017)

I did treat the bentgrass with tenacity last summer also, but I don't believe I got it all. I have tremendous amounts of snow mold currently and Ive read that bentgrass is very susceptible to snow mold.


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## g-man (Jun 15, 2017)

Tenacity is not a PreM. Tenacity is good at seed down, but it only lasts ~30 days. You will need to apply again, but you will reach the yearly max really fast.

The spring prem, is mainly for crabgrass. Dandelions grew during the fall. The roots are developed and deep waiting for warm up. The spring prem will do nothing to it.

Also, be careful with tenacity and fine fescues, which I think you have some. The tenacity label explains the max rate.

To treat bentgrass, do light frequent apps with nis (foliar).


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## pennstater2005 (Jul 17, 2017)

From the Tenacity label regarding use as a pre emergent:

_Preemergence Application - Apply Tenacity at 4-8 fl. oz. per acre in at least 30 gallons of water per acre prior to weed seed germination. Do not exceed 5 fl. oz. per acre per application to perennial ryegrass or fine fescues or mixed stands that contain greater than 50% perennial ryegrass and/or fine fescue. Do not exceed 4 fl. oz. per acre to St. Augustinegrass sod. Make application close to anticipated weed seed germination. Tenacity should be combined with a preemergence herbicide such as Barricade 65WG Herbicide for extended control of key annual monocot weeds such as crabgrass and foxtail. In established turf, Tenacity is more effective as a postemergence application unless combined with another soil active herbicide._

PRG rate is 5 fluid ounces per acre.

Note it can be combined with Barricade for extended control of crabgrass amongst other weeds.

I'll be using using Tenacity alone this year for some control as I need to seed. I'll use 2,4 D or other herbicides 
as needed for weed control throughout the remainder of the year.


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## MarkAguglia (Jul 13, 2017)

Just curious, why wouldn't a spring preM prevent the dandelions from popping up still? If not Tenacity, what should I use then? Prodiamine? I was planning top follow up with 2,4 D in spring for any post emergent weeds. This stuff is hard to grasp at first... I need to hire someone to create a plan for me. Lol as much as I watch YouTube and read here its still tough to manage a plan.


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## pennstater2005 (Jul 17, 2017)

MarkAguglia said:


> Just curious, why wouldn't a spring preM prevent the dandelions from popping up still? If not Tenacity, what should I use then? Prodiamine? I was planning top follow up with 2,4 D in spring for any post emergent weeds. This stuff is hard to grasp at first... I need to hire someone to create a plan for me. Lol as much as I watch YouTube and read here its still tough to manage a plan.


The Tenacity would act as a pre M for thirty days. You would get much longer coverage from prodiamine which would suppress the crabgrass and other listed weeds longer.


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## pennstater2005 (Jul 17, 2017)

Are you planning on any spring seeding for bare areas?


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## g-man (Jun 15, 2017)

MarkAguglia said:


> Just curious, why wouldn't a spring preM prevent the dandelions from popping up still? If not Tenacity, what should I use then? Prodiamine? I was planning top follow up with 2,4 D in spring for any post emergent weeds. This stuff is hard to grasp at first... I need to hire someone to create a plan for me. Lol as much as I watch YouTube and read here its still tough to manage a plan.


Spring PreM = Prevent crabgrass (and other summer anuals) that shows up mid May thru July.

Fall PreM = Prevents Poa A and other winter annuals

Dandelions that you see now will need a post emergent control (Weed B Gon)


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## gene_stl (Oct 29, 2017)

You can use Dimension (dithiopyr)instead of Barricade (prodiamine) if you are going to seed later. Or Drive (quinclorac)


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## g-man (Jun 15, 2017)

Prodiamine is better to apply a rate that matches when you want to seed than dithiopyr. Quinclorac is a post emergent and not a prem. It is really good against crabgrass (included in weed b gon+ crabgrass control).


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## MarkAguglia (Jul 13, 2017)

I wasn't planning on seeding until recently. I overseeded in the fall and everything was great but coming out of winter my lawn is looking rough and there's some bare areas so I'm considering seed which I figured was another benefit of using Tenacity.


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## HomerGuy (Jun 5, 2017)

I'm following along here too as I'm in a similar boat. I seeded last fall and have some bare spots scattered throughout.

I may try a combination approach and try to drop a granular Pre-M over the good areas, and avoid those areas that need to be re-seeded. I'd hit those areas with Tenacity. Sounds like a good idea on paper, but implementation will probably be tricky.


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## MarkAguglia (Jul 13, 2017)

Glad this at least makes for an interesting topic. I have some clover throughout which is yet another reason Id like to try this out possibly. Really I figure if it doesn't work out I can always hit whatever pops up with Weed B Gon about 6 weeks later. Maybe I'm missing the boat on why this isn't a great idea for my situation, minus that it only lasts 30 days. But even then, won't I be doing multiple apps anyway?


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## GrassDaddy (Mar 21, 2017)

So the thing is Tenacity isn't fool proof for pre-em and if you use too much in a year it'll kill the good grass. It's also expensive. So when you say using it for a pre-em most people are thinking like regular pre-em.

Now you mentioned some weeds you want to take care of with it. The issue is for a pre-em, you water it into the soil. To kill weeds you leave it sprayed onto the weeds. Now there is an effect on weeds if you water it in but it's not much of an effect so if you are trying to kill bent you want it sprayed on the blades and left to soak in.

It ultimately comes to the right tool for the job. Now if you are seeding, then apply it as a pre-em when you seed down and go from there. Once the new grass is established, you would put down regular pre-emergent. Then you can spot spray remaining weeds vs blanket spray. If you do it this route, the blank spray to the soil should cause the existing weeds to change color (might not kill but will look white/whitish). So then you can spot spray after that, which then reduces how much the good grass gets sprayed.


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## Green (Dec 24, 2017)

As Grassdaddy explained, it can be done, but it's a bit fiddly. Last Spring and this Spring, I've been using Tenacity as both a post and short-term pre. The trick is to apply it with the surfactant in it at the 4oz/Acre rate (roughly half a teaspoon per 1000 sq ft), and enough water to also get it down lower (like 2 gallons of water). You can actually do two passes in opposite directions at the 2oz/Acre rate (0.25 tsp/gal/1000 sq ft, done 2x). It's best to do this a day before you expect rain, so it stays on the grass long enough to act as a post, but then whatever excess there is, gets washed into the soil and acts as a short-term pre, which lasts 4-6 weeks. If you have something like Bentgrass to kill, or you're seeding, this strategy would make sense. Then once the grass seed has germinated and been mowed a couple of times, you would follow it up with a regular pre-M or a second Tenacity app (no more than 6 weeks later). (That second Tenacity app, if used, itself then gets followed up 4-6 weeks later with a regular pre-M at the appropriate rate.) At that point, you'd have used 1/4 to half the amount of Tenacity you're permitted to use for a year.


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## MarkAguglia (Jul 13, 2017)

That's one thing I'm not too concerned about is using up my yearly amount of Tenacity. I hope to not need it the rest of the year. I'm essentially debating whether or not I'm moving my fall overseed to spring. I also did just overseed this past fall. If I don't do this I may just get a regular Pre-M like a granular prodiamine and use Tenacity in the summer/fall.


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## pennstater2005 (Jul 17, 2017)

@MarkAguglia

Sounds like a plan. Keep us posted. I'll be doing something similar so I'll be curious as to what you thought.


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## MarkAguglia (Jul 13, 2017)

I'm still a newbie so tell me YOUR plans, haha.


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## pennstater2005 (Jul 17, 2017)

MarkAguglia said:


> I'm still a newbie so tell me YOUR plans, haha.


You joined before me so I'm the newb :lol: My plans are similar to yours I think. I'm going to get Tenacity down this weekend with plans to seed the bare areas as I don't feel like spraying prodiamine around all that. Then at some point after that I'll consider using a pre m but if the weed pressure is too great I'll probably just spray 2,4 D and triclopyr as needed.


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## MarkAguglia (Jul 13, 2017)

I like watching GCI Turf on YouTube, Pete uses a pre-M and yet seeded spots by using a garden weasel to basically break up the pre emergent in just those particular areas. That's another thought to consider.


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## pennstater2005 (Jul 17, 2017)

MarkAguglia said:


> I like watching GCI Turf on YouTube, Pete uses a pre-M and yet seeded spots by using a garden weasel to basically break up the pre emergent in just those particular areas. That's another thought to consider.


That's actually a good thought to consider. Would that actually work? Why not just avoid those areas then when putting down one's pre m I wonder?


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## social port (Jun 19, 2017)

@MarkAguglia I found myself in a similar situation this year. I did a reno last fall, but my grass was too immature this spring when it was time to apply a PreM (Dimension, for example, can be safely applied after 2-3 mowings of new grass; otherwise there is risk for turf damage). So instead of using a traditional preM, I used tenacity. It worked very well for five weeks, but I will be using a traditional PreM as soon as possible (the Tenacity is no longer active).

Bottom line: Tenacity worked great for me as a Pre-M this spring, but it is short-lived and expensive. In granular form, it usually comes packaged with fertilizer (with an analysis consistent with starter fertilizer), which may or may not be a problem for you. Prodiamine and Dithiopyr are standard preMs for a reason, but sometimes certain situations make Tenacity a better alternative--albeit a temporary one.



MarkAguglia said:


> Pete uses a pre-M and yet seeded spots by using a garden weasel to basically break up the pre emergent in just those particular areas. That's another thought to consider.





pennstater2005 said:


> That's actually a good thought to consider. Would that actually work? Why not just avoid those areas then when putting down one's pre m I wonder?


I also think that is an interesting idea. If the preM works by establishing a barrier across the soil, then disrupting that barrier should decrease its effectiveness on inhibiting germination. I imagine, however, that the risk is opening up the soil for germination from all seeds--not just the grass seed that you're putting down. Then, your grass seed will be in competition with weed seeds for nutrients, water, and sunlight. Not to mention, later on, the crowding of plants that are trying to establish. That is when Tenacity becomes very useful. But I'm just speculating here.


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## MarkAguglia (Jul 13, 2017)

So, how about this...

Put down a traditional Pre- M, prodiamine or dithiopyr over the entire lawn. Then, using something like a garden weasel, break up the surface in areas that I need to seed. Throw down seed and cover with peat moss. Finally, hit just those spots with Tenacity.

Side note - For me, the argument of Tenacity being too costly isn't an issue because I already have a bottle and it looks like itll last me years! Plus then Id have to go buy a Pre-M. So to say its expensive...by using it id be saving money this year.


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## social port (Jun 19, 2017)

@MarkAguglia I really don't know...but as long as you think of this as an experiment, what's the harm? Give it a go and let us know.

I'm not sure which Professor Pete video you have in mind...but I would pay close attention to how deep he goes into the soil and also make sure that he doesn't bring in fresh dirt. Whatever the case, I don't think you will go wrong following his lead.


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## MarkAguglia (Jul 13, 2017)

He just breaks up the soil and top dresses with compost.

Video below:

https://youtu.be/R-3VSi978sU


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