[Pete1313]

I had someone reach out to me recently about a fall renovation and they put down 5lbs/1000 sq ft of .37% prodiamine on March 31st. Can someone check my math as I said that they put down a 7 month barrier of prodiamine. Also I suggested coring and then verticutting(slit seeding) to break up the barrier before seed down. Anyone have any success or other tips when someone wants to renovate after putting down this type of rate.

Did the math on the prodiamine rate.
You did 5 lb/1000 of .37%
5×.0037=.0185 lb/1000 of AI(prodiamine)
To convert to amount/acre
.0185×43.56=.80586 lb/acre of AI
.80586 lb/acre rate of AI provides protection for up to 7 months. Unfortunately if you plan on seeding this year you will need to disturb the soil.

A .80586 lb/acre rate of AI is the equivalent to 1.25 lb/acre of prodiamine 65 WDG.

 

[g-man]

Some of the granular products have a table of month prior to overseed. https://www.domyown.com/msds/007_prodiamine.pdf

4.9lb/ksqft of the 0-0-7 0.37% prodiamine has *** for North and 6 months for transition / south.

Heavy aeration and above normal seed rate is the only thing I could think of doing.

 

[j4c11]

I can confirm heavy core aeration does the job.

 

[KHARPS]

Hi everyone! My name is Kevin and I'm the one who reached out to Pete about help with a renovation. As Pete mentioned, I followed the LCN's advice and put down 5lb/m of 0.37 Prodiamine on 3/21. According to his newsletter, or whatever you want to call it, that was supposed to give me a good 3-4 months coverage. Through my own research (reading the label and browsing on forums) I realized I may have made a mistake since I planned on doing a renovation and Pete has confirmed that for me. I have so many questions for you guys but I don't even know where to begin! I'm hoping you can help me break this Prodiamine barrier and give me any advice to set myself up for a successful renovation using either 100% bewitched or a bewitched/ award/ midnight trifecta. I have 20lb bewitched and 10lb award/midnight blend and approximately 7,000 sq ft backyard and 3,000 sq ft front/side yard.

 

[g-man]

I would aerate now (this weekend) since we had rain and the soil is soft. I would go multiple passes. I would then aerate again a week before seed down.

Prodiamine has a half life and you will be approaching it's end of life. It has a reduce effect as time goes on. I would then also go a little more on the heavy side of seeds qty/ksqft.

Edit:
I just remember into this study by Purdue (Boiler up!). I was wrong. Look at treatment 20, it was at 0.75ia/acre and it still had 89 control in August. https://turf.purdue.edu/report/2011/PDF/15_AGRY_Patton_sequential%20apps.pdf

Therefore aearate a lot and have a backup plan if thing don't go as planned.

 

[Pete1313]

@KHARPS welcome to TLF! It does sound like aeration is what is going to be needed in your situation. I would core it up and then drag it smooth like I did before seed down or you could core and then run over it with a verticutter/slit seeder in a few passes before seeding.

 

[KHARPS]

Welp, not really the reassurance I was hoping to get. Here's the quote from LCN's pre-emergent strategy guide:

"If you are following my strategy of a triple application, then your first application is this Prodiamine 0-0-7. It will be made in early spring, sometime after the forsythia bloom. Maybe around the time you see Red Bud trees blooming, and the first set of spring tulips is popping.
The rate I recommend here is 5LBs/1000 SF. That will give you a very strong 3-4 month residual as long as you keep foot traffic on the lawn minimal. At that rate, this bag will cover 10,000 square feet at a cost of about $54. If you have a smaller lawn, you can pack this away in a dry, dark place and use the rest next season."

I guess I have a tough decision to make here soon. Beat the crap out of the soil over the next month to month and a half and gamble with seeding...or wait until next year to renovate and put down a much lower rate of Prodiamine in the spring.

 

[g-man]

I don't understand his recommendation. 3 applications of prodiamine at that rate will exceed the yearly max. I discussed with the grassfactor doing a 3 apps splitting the yearly max, but I haven't tried it.

LCN joined the site, but hasn't posted. I'm not sure if he is reading, but I will ping him. @LawnCareNut . If it is a mistake he should know to fix it or explain the rational. Maybe that coukd be the dimension rate.

 

[KHARPS]

Come to think of it, a 2019 reno probably won't be in the cards. We have to host a family event the second weekend in August which we will need to have a yard for. So hopefully LCN can chime in here. I sent him an email yesterday so I'm hoping for a response there potentially.

 

[KHARPS]

Here is a quote from LCN's most recent newsletter in regards to fall overseeding after applying not only the spring app of Prodiamine granular @ 5lb/1000 (.805 lb/acre AI) but also a June app of Dithiopyr on top of that.

"Quick Thought: Fall Seeding - If you apply dithiopyr here in later June, we are going to run into the fall seeding time as far as residual goes (I'm talking cool season lawns here).

I typically recommend most of you in the midwest, north and northeast to do your fall aeration and overseeding in early September, even late August if you can pull plugs and are irrigated. This means that applying your dithiopyr with a 12-14 week residual is putting you clearly into September and that is "no bueno" for new grass seed. Fear not though, a good double pass aeration will break up that barrier enough to be fine with your fresh overseeding.

Additionally, with all the watering you will need to do after (seed needs water daily to grow) that will wash out any remaining dithiopyr, but ONLY if you have first aerated. This is what aeration is best for: creating a nice seed bed in an existing lawn for fall overseeding."

So according to @LawnCareNut, a good double aeration will break up not only the spring Prodiamine app @ 5lb/1000 but also an app of Dithiopyr in late June @ 4lb/1000. I have been doing some searching around on here and elsewhere and I haven't been able to find too much info on this predicament I put myself in. What do most of you who are planning on renovating in the fall put down in the spring? Just a lower rate to get you by for 4 months?

 

[Pete1313]

What do most of you who are planning on renovating in the fall put down in the spring? Just a lower rate to get you by for 4 months?

The last 3 renovations I did had no spring pre-m of any kind. Whatever that was going to pop up was going to be killed with glyphosate in june.

 

[KHARPS]

I should add that @thegrassfactor was a technical advisor for @LawnCareNut 's pre-emergent guide that listed the Prodiamine rate I used for 3-4 months coverage. Can anyone else weigh in on if I should carry on with my proposed renovation? I'm on board with a double aeration and verticutting before broadcasting the kbg.

 

[thegrassfactor]

I should add that @thegrassfactor was a technical advisor for @LawnCareNut 's pre-emergent guide that listed the Prodiamine rate I used for 3-4 months coverage. Can anyone else weigh in on if I should carry on with my proposed renovation? I'm on board with a double aeration and verticutting before broadcasting the kbg.

Hey @KHARPS, a couple of things I've learned here:

1. I think an addendum pertaining to lawn renovations should be added to the guide. The guide was not designed with a renovation taking place, and that can certainly be addressed. The three pre series was designed for existing Kentucky bluegrass lawns that could fill in on there own without a renovation or a little touch up seed: 2 apps of prodiamine, 1 app of dimension.

2. .8lbs AI of prodiamine will provide *up to* 7 months control in a dense stand of turf. The likelihood of this effecting the energy stored in a hybridized turfgrass is slim, but can definitely exaggerate the sprout and pout symptoms it's known for. I would usually recommend by averages because of application error, weather fluctuations, excessive rain faill, excessive heat, bare ground exposure, all speed up the decay of prodiamine.



To ease your fears, I apply ~ .75lbs of AI in May to 100+ acres of fescue to turn around and seed it in September with no issues.

Lastly, prodiamine exists as a vapor barrier throughout the soil surface. Anything to disturbed the vapor connectivity will break the efficacy of the herbicide. On a professional level, we spray with round up, triple or quad aerate, and then use something to smooth the soil surface into a powder like state (I use a baseball diamond nail drag). This ultimately ruins all traces/instances of prodiamine.

I hope somewhere in there I made you feel a little better about it all.

Most of all, thank you for bringing this to my attention!!

 

[g-man]

:thumbup:

 

[KHARPS]

@thegrassfactor thank you very much for weighing in. Your response on the subject has definitely eased my fear with the pre-em preventing seed from germinating. To make a long story even longer, there's someone from the city that is supposed to come out and take a look at the major drainage problem in my yard that is caused by the park behind my house being at a higher elevation and lack of storm sewer between their property and mine. If all goes well I will be having some drainage work done and the back yard graded which should greatly disturb the pre-em barrier.

 

[LawnCareNut]

Aeration will do fine to break it all up, I promise. Aeration is good for your soul too. It will teach you about being a man, just sayin.
Also, I guess I need to understand the term "renovation" better. If someone had planned to do a full reno (glypho kill, scrape, seed) then there should have never been any need for fert, pre-M, weed control, none of it. Just mowing and blowing I'd suspect. And if the plan has changed mid-year... like at first there was no reno planned, but now, here in the summer, a reno is planned - that's not the fault of the guide. That's just a change in plan and changes in plans require changes in strategy and sometimes that's not always ideal - hence the wonderful world of lawn care we live in.

Now if you are going to do a reno of the type that is just aeration and overseed of an existing lawn - and the fact that you have applied pre-emergent bothers you-- then I say just skip the seeding and fert the crap out of the lawn every 4 weeks starting in late AUg. Hit that puppy every 4 weeks with my best friend Milo and watch it blow up.
If that picture above is the yard you are talking about - then those flooded areas have 0 chance of any pre-emergent remaining anyway. The rest of the lawn is super tits awesome and I see no need for a reno.
Long story short - aerate and hope for the best. Apply seed heavy - like 10lbs/1000 and water water water. Most seed applications fail because of lack of moisture.
Finally, It has also occurred to me that this thread may have multiple streams of thought in it - both caused by my poor reading comprehension skills, and the fact that you are getting advice from multiple sources. Context is always key and quite often I get email from people who have started one program and course, changed, gone to someone else, then come to me for advice. Those situations never work out well. In the end, it's just lawn care. Thrower down and hope for the best. Seed is cheap. .

 

[Pete1313]

If someone had planned to do a full reno (glypho kill, scrape, seed) then there should have never been any need for fert, pre-M, weed control, none of it. Just mowing and blowing I'd suspect.

I 100% agree, no need for pre-M in a full reno year. Just keep it alive and plan a quick release fertilizer a couple weeks before the kill. Keeping it growing well before the glyphosate will get a better kill.

Apply seed heavy - like 10lbs/1000 and water water water.... Seed is cheap. .

I disagree with 10 lbs/M of seed for a 100% KBG reno. I understand increasing the rate because of the chance that the Pre-M might decrease some germination. I had good success seeding at 2 lbs/M on my reno. In your situation I might increase the seed rate to 3-4 lbs/M. Too much seed/germination will increase the chances of a fungus in a first year lawn.

 

[g-man]

@Pete1313 The lb/M of seed depends on the seeds. TTTF goes at a higher lb rate than kbg. But in agreement, too much seed might cause fungus problems.

 

[Pete1313]

Pete1313 The lb/M of seed depends on the seeds. TTTF goes at a higher lb rate than kbg. But in agreement, too much seed might cause fungus problems.

Agreed, @KHARPS is planning a 100% KBG reno.

I'm hoping you can help me break this Prodiamine barrier and give me any advice to set myself up for a successful renovation using either 100% bewitched or a bewitched/ award/ midnight trifecta. I have 20lb bewitched and 10lb award/midnight blend and approximately 7,000 sq ft backyard and 3,000 sq ft front/side yard.

 

[KHARPS]

@LawnCareNut thanks for weighing in, Mr. Nut. You are correct that a renovation was not my original plan for this year although multiple factors have influenced me to do one. 1) I had irrigation installed in May, 2) there is a serious drainage and grading problem I want to address, 3) I have an overwhelming amount of grassy weeds that I want to nuke with roundup before they go dormant this summer, 4) I'm not thrilled with the northern mix this lawn has. I know I'm throwing this renovation together under less than ideal conditions and I have to do a lot of work in order for it to be successful but I'll have all of July to kill, aerate, grade, have drainage work done, and get seed down either first or second week in August.