# Trying to understand PGR and when to apply it.



## silvercymbal (Sep 17, 2018)

Hi, I am in Mass and wanted to start to use this probably next year at this point. I am wondering when to apply this or maybe even what your schedule is. I feel like a I get a ton of top growth and after a lot of renovation work this year my lawn got much better, still needs a lot. I am working to mowing low and I am hoping this will encourage the spreading of the grass as well. I am unsure when to apply though for this growing season. Any help is greatly appreciated.


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## zeus201 (Aug 30, 2017)

Check out the link in the cool season sticky about PGR, lots of great info there as well.

Basically you can start after the second mow of the season. I started around the first week of May and applied every other week at rate of ~0.40oz/M and stopped mid September.

However, there are several members here who use the GDD model to help with application timing. I have not reached that point yet and created a calendar reminder to apply PGR.

I also used some NIS to help with adhesion to the leaf blades. Unsure if helped but it did not harm anything. If I remembered I'd toss in some liquid iron @ 1oz/M to help add some color. But I swore just PGR made the grass greener / darker.

I love the stuff and will use as long as I am reel mowing or maintaining a shorter HOC.


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## SNOWBOB11 (Aug 31, 2017)

Give this thread a look https://thelawnforum.com/viewtopic.php?f=9&t=533. The general idea is you can start after you mow the grass twice in the spring and can apply around every 3 weeks if your using primo. There are other ways to get the timing of apps down such as GDD (growing degree days). You want to be careful applying if fungas is a issue. Other than that just apply when you want to suppress growth.


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## silvercymbal (Sep 17, 2018)

SNOWBOB11 said:


> Give this thread a look https://thelawnforum.com/viewtopic.php?f=9&t=533. The general idea is you can start after you mow the grass twice in the spring and can apply around every 3 weeks if your using primo. There are other ways to get the timing of apps down such as GDD (growing degree days). You want to be careful applying if fungas is a issue. Other than that just apply when you want to suppress growth.


Very cool! Thank you I will definitely check that out for sure. I really appreciate it.


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## SNOWBOB11 (Aug 31, 2017)

Looks like I kind of said basically the same thing as you @zeus201. Didn't mean to copy but wrote my post up already so I just figured I'd post.


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## Green (Dec 24, 2017)

When I first started messing with it a few years ago, I used full rate. That turned out to be overkill. I now use a fraction of the full rate (half to a third); this works well for the results I like.

Something else to keep in mind is that the effectivness interval really doesn't change much due to the rate of T-pac spray you use. It's mostly determined by temperature...but always seems to be close to 3 weeks.


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## zeus201 (Aug 30, 2017)

SNOWBOB11 said:


> Looks like I kind of said basically the same thing as you @zeus201. Didn't mean to copy but wrote my post up already so I just figured I'd post.


No worries!!!


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## silvercymbal (Sep 17, 2018)

Green said:


> When I first started messing with it a few years ago, I used full rate. That turned out to be overkill. I now use a fraction of the full rate (half to a third); this works well for the results I like.
> 
> Something else to keep in mind is that the effectivness interval really doesn't change much due to the rate of T-pac spray you use. It's mostly determined by temperature...but always seems to be close to 3 weeks.


Interesting. I don't mind the mowing frequency at all. My main hope is for better coloration and denser turf. I am excited to try it. I also need to get my sprayer setup going over the winter ready.


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## g-man (Jun 15, 2017)

zeus201 said:


> But I swore just PGR made the grass greener / darker.


This is a real thing. Since the top grow is reduced (or stopped), the chlorophyll concentrates on the available leaves. The inverse effect happens when the grass is growing really fast and turns pale green.

Besides less mowing, there is less need for water and nitrogen too. Overall it is a good thing. I've followed gdd this year. It was great.


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## JDgreen18 (Jun 14, 2018)

I have been wondering about this myself, does hoc matter as to who uses PGR? What I mean is to maintain the 1/3 rule is a big difference for someone with hoc of 1 inch or less and someone with 3-4 inch. I understand and makes sense to me that someone maintaining a very low hoc to use otherwise you would be mowing everyday.


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## drenglish (Jun 22, 2018)

@JDgreen18 I'm interested in this too as some of my lawn I'll maintain at 3-4" and would like to benefit from the decreased mowing/increased color if possible.


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## JDgreen18 (Jun 14, 2018)

drenglish said:


> @JDgreen18 I'm interested in this too as some of my lawn I'll maintain at 3-4" and would like to benefit from the decreased mowing/increased color if possible.


I don't necessarily want to mow less mowing thickens the lawn, plus I actually like it. I usually mow once or twice a week depending on rain and how much I feed it. My biggest question is what is the benifet of using it on a higher HOC.


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## g-man (Jun 15, 2017)

The link that snowbob shared discussed the higher hoc. The benefits are the same (greener, more root mass, less mowing, less water).


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## Green (Dec 24, 2017)

silvercymbal said:


> Interesting. I don't mind the mowing frequency at all. My main hope is for better coloration and denser turf. I am excited to try it. I also need to get my sprayer setup going over the winter ready.


Half rate definitely increases mowing time by a few days, but the biggest difference was the color improvement. When I did full rate, it grew too slow for my liking. I'm mowing about once a week using 1/3 of full KBG rate, but could be doing it sooner at times...sometimes it gets a bit overgrown. If you mostly want color and density improvement but still want to mow every 5-7 days, I would go with 1/3 of the full KBG rate, regardless of grass type. I'm at 3.75 inch HOC. It doesn't grow slow enough to be annoying this way.


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## JDgreen18 (Jun 14, 2018)

Green said:


> silvercymbal said:
> 
> 
> > Interesting. I don't mind the mowing frequency at all. My main hope is for better coloration and denser turf. I am excited to try it. I also need to get my sprayer setup going over the winter ready.
> ...


How does it Increase density when its growing less....also I thought mowing increased density? So wont you want to mow more.


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## Green (Dec 24, 2017)

JDgreen18 said:


> Green said:
> 
> 
> > silvercymbal said:
> ...


I guess because since you're inhibiting it from going up as much, it redirects the growth by making more leaves...very similar to what mowing does, and I wouldn't be surprised if the mechanisms were similar, but I'm not sure. The PGR is actually inhibiting hormones that make the grass grow fast.

Still mowing often at 1/3 of full rate, in any case.

The color increase is supposed to be because the chlorypyll cells are closer together due to less growth during the same unit time.


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## Green (Dec 24, 2017)

JDgreen18 said:


> So wont you want to mow more.


Yeah. I just don't always get to it as soon as I'd like.


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## drenglish (Jun 22, 2018)

Well, I'm sold on the above benefits. I just hope someone will divvy up gallon of PGR in the exchange thread soon. If not I'll buy a gallon and either part it out for find places to spray it haha


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## JDgreen18 (Jun 14, 2018)

> I guess because since you're inhibiting it from going up as much, it redirects the growth by making more leaves...very similar to what mowing does, and I wouldn't be surprised if the mechanisms were similar, but I'm not sure. The PGR is actually inhibiting hormones that make the grass grow fast.


@GreenThis was line of thinking which is why I was asking.... so besides the color increase it seems to me that the benefits really are more geared for the shorter cutting lawns, unless you just want to mow less.


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## Green (Dec 24, 2017)

@JDgreen18

That and supposedly better drought performance, but I'm not sure how much difference it makes for that.


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## silvercymbal (Sep 17, 2018)

Why can't I apply this stuff now? Damn New England!!! This stuff sounds very cool - Instead I need to close my sprinklers today


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