# How long to wait after RU before mowing?



## Green (Dec 24, 2017)

I sprayed generic glyphosate today, and would like to mow tomorrow. It's just not practical in this case for me to wait a few days, because the grass hasn't been mowed yet this year, and there is also rain in the forecast many of the next few days.

Is it ok to mow so soon after?


----------



## ryeguy (Sep 28, 2017)

This study experimented with timing of pre- and post-glyphosate mowings of different lengths. It states "our preliminary data indicate that tall fescue control with glyphosate is not reduced by scalping as soon as one day following treatment".

So you should be good with just 24 hrs.


----------



## Green (Dec 24, 2017)

Thanks. That's very helpful. I think I'll take off as little as possible tomorrow, and possibly mow around some patches as well.


----------



## llO0DQLE (Dec 4, 2017)

I specifically remember guys over on ATY (JG, TT and/or Andy IIRC) stating they've scalped the day after or even the same day after spraying RU. I believe it was JG that tried it the same day, spray in early AM and scalp late PM - and it still worked. Seeing as the best thing to do is scalp around 2-4 days after spraying before the grass gets matted down, I think you'll be fine with doing it the day after. The only thing is if your grass was in need of a mow when you sprayed, there might be turf under the canopy that didn't get hit with RU, depends on how much you drenched it.


----------



## Green (Dec 24, 2017)

@llO0DQLE, good info and good point about likely missing some due to high grass. I hadn't mowed yet when I sprayed, and it was over 4 inches. I expect to have to spray at least once more, if not twice before reseeding. No time to fallow, unfortunately, as Spring seeding in full sun is very risky here due to the Summer heat and humidity.

I'm going to know again one of these days to go down a notch.

Not much browning yet.

I originally wanted to do a compost topdress while seeding, but no time and don't need more weed seeds, so probably not going to.


----------



## llO0DQLE (Dec 4, 2017)

I would mow it down to 2" then spray RU then scalp.


----------



## Scagfreedom48z+ (Oct 6, 2018)

I applied glypho with marker dye on 5/4 
I mowed on 5/6 to scalp it down and reapplied glypho again with marker dye.

I used a Lesco surfactant and also dropped the ph down using citric acid to 5 or below.

I still haven't seen any relevant die off.

Did I do something wrong by dropping the PH?


----------



## ryeguy (Sep 28, 2017)

Regular glyphosate without additives (like Diquat in name brand roundup) can be a bit slow to see results, sometimes the better part of a week. The blue dye looks a bit heavy which could be covering up the visual cues, too.

I'm unsure if lowering the ph can have a negative effect, but what made you do it?


----------



## MassHole (Jun 27, 2018)

Scagfreedom48z+ said:


> I applied glypho with marker dye on 5/4
> I mowed on 5/6 to scalp it down and reapplied glypho again with marker dye.


That's a massive color shift. What's your plan for the area?

Poa triv?


----------



## FuzzeWuzze (Aug 25, 2017)

Scagfreedom48z+ said:


> I applied glypho with marker dye on 5/4
> I mowed on 5/6 to scalp it down and reapplied glypho again with marker dye.
> 
> I used a Lesco surfactant and also dropped the ph down using citric acid to 5 or below.
> ...


Your not going to really see much that quickly, you need to wait at least a week before you'll start to see things dying off. The marking blue will make it a bit harder as well until it washes off.


----------



## Scagfreedom48z+ (Oct 6, 2018)

MassHole said:


> Scagfreedom48z+ said:
> 
> 
> > I applied glypho with marker dye on 5/4
> ...


That's going to be the kids playground. Once that grass dies off within the black borders, it's getting covered with playground wood chips.

The grass in front of it the black borders will
Be killed off in my fall Reno. I have quite a bit of triv and bentgrass in that area


----------



## Green (Dec 24, 2017)

I sprayed a week ago and am seeing a lot of brown in those areas today.


----------



## Scagfreedom48z+ (Oct 6, 2018)

ryeguy said:


> Regular glyphosate without additives (like Diquat in name brand roundup) can be a bit slow to see results, sometimes the better part of a week. The blue dye looks a bit heavy which could be covering up the visual cues, too.
> 
> I'm unsure if lowering the ph can have a negative effect, but what made you do it?


I just took the mindset that it seems that certain applications like fungicides,insecticides, herbicides etc seems to work more effectively when the PH is lower. I have well water is it's typically pretty acidic, around 9 or so. I was concerned that the high acidity would render the glypho not as effective


----------



## Green (Dec 24, 2017)

Scagfreedom48z+ said:


> I just took the mindset that it seems that certain applications like fungicides,insecticides, herbicides etc seems to work more effectively when the PH is lower. I have well water is it's typically pretty acidic, around 9 or so. I was concerned that the high acidity would render the glypho not as effective


Suburbanjunglelife advocated testing and if needed, lowering the pH using citric acid if storing. I didn't bother, because I used up the stuff in 15 minutes. I did use filtered water, though.


----------



## ken-n-nancy (Jul 25, 2017)

Scagfreedom48z+ said:


> I have well water is it's typically pretty acidic, around 9 or so. I was concerned that the high acidity would render the glypho not as effective


Acidic well water is pretty common in the northeast due to the soil and bedrock being naturally acidic in our area.

However, a pH of 9 would not be acidic, but would be a moderately strong base (alkaline) roughly equivalent to baking soda. I speculate you're not remembering the pH level of your well water correctly, as a pH of 9 would be water exceeding the EPA recommended pH for well water.


----------



## Suburban Jungle Life (Mar 1, 2018)

I always put ams in the water and mix before adding gly. Gly likes to bind with minerals in water and leaves less available for use. Ams stops this. My water is 7 ph and with 2.5 oz/gal of ams, it lowers it to about 6 ph. That's good for gly. If you have 9, I would also add citric after ams and gly to lower it more. Check ph after gly as gly depending on what you buy can lower ph already. High ph can reduce efficacy.


----------



## Scagfreedom48z+ (Oct 6, 2018)

Thanks guys for the feedback!


----------



## FuzzeWuzze (Aug 25, 2017)

If this is getting covered in mulch it might be worth respraying it with Roundup 365 (very carefully!) for a total kill that sticks around .


----------



## Scagfreedom48z+ (Oct 6, 2018)

12 yards later and 1500 Sq ft of heavy duty weed cover...


----------



## g-man (Jun 15, 2017)

Did the round up work?


----------



## Scagfreedom48z+ (Oct 6, 2018)

It did, this was a good test for later this year. I was expecting the round up to kill it much quicker


----------

