# Does Glyphosate Go Bad?



## rjmoses (Apr 4, 2010)

I had about 1/2 of 2.5 gallon container of glyphosate leftover from last year. I mixed up a batch to spray the driveway at 2 oz in 3 gallons of water. It seemed like it had no effect whatsoever!

I checked the container and it had a mold around the top at the cap and some in the glphosate itself. I've never seen this before.

Any thoughts?

Ralph


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## slowzuki (Mar 8, 2011)

That’s very odd, I’ve got 3 year old stuff that is left out in -30, never had a problem. What brand?


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## r82230 (Mar 1, 2016)

Generic? I have RU Max that's several years old (subject to freezing in the winter even), that still works (perhaps I should knock on wood).

Larry


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## mlappin (Jun 25, 2009)

Never had round up go bad nor any of the generics and its left out in the winter. Have also never seen it mold.


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## r82230 (Mar 1, 2016)

Mold might be a clue, perhaps it was already diluted (field ready to spray and put back into container, without marking it, my wife knows someone who has done this, BTW). :huh:

Larry


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## rjmoses (Apr 4, 2010)

r82230 said:


> Mold might be a clue, perhaps it was already diluted (field ready to spray and put back into container, without marking it, my wife knows someone who has done this, BTW). :huh:
> 
> Larry


I normally don't do this, but a helper might have poured an unused diluted portion back in the original container.

Ralph


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## Hayman1 (Jul 6, 2013)

I have never had RUMax or generic go bad on me over a year. I usually never have much more that part of a 2.5 gal container left in fall and it usually gets used up in the first combat.


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## NewBerlinBaler (May 30, 2011)

The responses above run counter to my own experience. When I've applied year-old Round-Up, it's been totally ineffective.


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## IH 1586 (Oct 16, 2014)

I have generic RU been using for years and still effective. It's at least 5 years old if not more.


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## endrow (Dec 15, 2011)

I know there's a lot of chemical dealers around they have inventory when the season ends and they sell that again next year. Our chemical dealer says there is not a problem with keeping it over till the next season but they are not supposed to allow it to freeze . If you keep a jug in the garage for a couple years and knock a couple weeks down behind the shed yeah it's going to work. But if you're caught with 25 gallons in your bulk tank and let it sit all winter in your three-sided Machine Shed freezing and thawing all winter and you go to spray a 18 inch cover crop thick as a hair on a dog at 28 oz to the acre you might be a little disappointed with some of this product from what I hear. We try to keep a bare minimum for carry over on our farm and what we keep we do not allow the freeze


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## Vol (Jul 5, 2009)

I have not had issue with unused/carryover glyphosate in this region....nor do I know of anyone mentioning trouble either. I usually have carryover that endures the cold temps in the storage room.

Regards, Mike


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## slowzuki (Mar 8, 2011)

I should say I had bad luck at least once saving mixed roundup. Didn’t use a full load once so drained off the dregs to use in hand sprayer. The following year it didn’t work well but I’ve always assumed it was due to our very hard water.


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## somedevildawg (Jun 20, 2011)

Never had an issue and I always seem to have some carry-over....but, I never let it freeze  it takes a lot of discipline, have to always remember where the Gly is.....thinking about building a separate insulated building so I don't have to worry with inclement Wx in the future


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## Taylor.Jackson (Sep 30, 2016)

did you say 2 oz per gallon, or 2 oz in 3 gallons.


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## rjmoses (Apr 4, 2010)

Taylor.Jackson said:


> did you say 2 oz per gallon, or 2 oz in 3 gallons.


2 in 3.

Ralph


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## Hayjosh (Mar 24, 2016)

My dad worked for Monsanto for a long time and is still a marketer in the seed business. He always told me I shouldn't let my glyphosate freeze as it lowers its potency, as does age to some extent. That being said, I have Glyphosate that is several years old--and I did even leave out in the barn one winter--and it still seemed to kill, but I no longer let it freeze.


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## pede58 (Oct 27, 2015)

I've always been told sunlight is the biggest killer of potency.


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## Wethay (Jul 17, 2015)

If it's 41%, and my math is right, 2 oz/ 3 gal is right at 1/2%. I'm usually at 1 1/2% or a bit stronger for use in my backpack. Of course that,s not figuring any additional potency from the mold. I tend to use a bit of surfactant also.


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## broadriverhay (Jun 13, 2014)

3 oz. per gallon will kill but I use 4 to 6 oz per gallon for a little quicker kill on taller weeds when sprayed with backpack.


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## Taylor.Jackson (Sep 30, 2016)

Thats what I was getting at. Im no herbicide expert but 2 oz in 3 gallons seems pretty weak.


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## Vol (Jul 5, 2009)

I use 2 ounces per gallon minimum in a handheld sprayer.

Regards, Mike


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## pede58 (Oct 27, 2015)

I'm kind of getting away from using gly, and if it wasn't such a good grass killer probably wouldn't use it at all. In the past I have used 64ozs per acre with 10gal water so by my math in a handheld that would make 6.4ozs to the gallon. My sales rep always said go big or go home.....good thing he is a friend or I'd think he was trying to sell more product.


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## StxPecans (Mar 3, 2018)

I have usedyear old juggs all the time no issue. My dad is bad about unhooking the sprayer with 50 gallons of glysophate mixture in the tank and a few months later in the sun its still good. Might get nasty and stop up nozzels but it kills.

Always been told sunlight kills it.

I use 1.5% at 15 gallons an acre with no issues. Even have gone down to 10 gallons an acre with good success. I use either generic with a good built in surfactant or add a good surfactant. Also add 1 gallon of 32% solution per 100 gallons seems to help kill. Spraying in pecan orchard to kill everything on orchard floor.


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## hog987 (Apr 5, 2011)

Just a question are you sure it was glyphosate? That nobody emptied the container out and put something else in jug? Having it go moldy is strange. I have some thats 3 years old and it still kills with hand sprayer. Mind you i really soak the weeds with the wand.


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## rjmoses (Apr 4, 2010)

hog987 said:


> Just a question are you sure it was glyphosate? That nobody emptied the container out and put something else in jug? Having it go moldy is strange. I have some thats 3 years old and it still kills with hand sprayer. Mind you i really soak the weeds with the wand.


I don't know. Something strange happened that I've never seen before--but, then again, there a lot of things that I've never seen before.

Ralph


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