Does Roundup go bad?

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Old 06-13-19, 04:00 AM
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Does Roundup go bad?

I've had a couple experiences now where i've mixed Roundup from concentrate according to label instructions and weeds don't die. Positive that i'm mixing it properly; i'm using a pump-up sprayer and wetting the leaf surfaces of the weeds.

I bought the container last year and now i'm wondering if it went bad in the garage, due to colder winter temps? Any ideas? Thanks!

 
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Old 06-13-19, 04:10 AM
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No! It can be stored year after year.
 
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Old 06-13-19, 04:23 AM
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How long ago did you spray the weeds?

Did it rain or did sprinklers irrigate after you sprayed?

Were you spraying weeds resistant to glyphosate?


Glyphosate (RoundUp) can be stored almost indefinitely in it's original concentrate form and if it's already diluted in it's original container. The only time I have seen generic glyphosates go "bad" was when it was diluted with water and not used in a reasonable length of time. It can form a jell or snot in the sprayer which I beleive is more a fault of the water and not the herbicide. Still, even bad it killed weeds.
 
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Old 06-22-19, 05:19 AM
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Sorry for the delayed response, and thanks for your replies. Turns out i was expecting to see weeds die after 3 days and the target weeds, japanese stiltgrass, were not even looking unhappy at that point. Now that more time has passed those weeds are dead. I read that stiltgrass is not necessarily resistant but can need more attention with Roundup, such as mixing dishsoap in to make the fluid adhere better. All that was really needed was appropriate expectations.

Thanks again!
 
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Old 06-22-19, 08:22 AM
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Similar expectations that seemed to fail, but time did the job extremely well. For me it seemed to go into the soil and killed well outside of the direct spray area. Nice.

Bud
 
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Old 06-22-19, 10:30 AM
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Most formulations of glyphosate and RoundUp brand already contain a surfactant. If the mix foams when adding the water then it already has surfactant (soap). If you want to add more then make it the last addition to your sprayer to minimize foaming.

Glyphosate is deactivated on contact with the ground. Whenever you see death around where you sprayed it is over spray. Everyone says they don't have overspray but you do. You can see the large droplets coming from your sprayer but you often can't see the extremely fine particles also coming out and those fine particles can drift pretty far in a breeze and it's enough to kill or severely harm most plants.
 
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Old 06-22-19, 10:43 AM
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The gallon container I purchased comes with a spray want and a pump handle. Pump it up and shoot. But it does nor deliver a spray, only a single stream of RU. I expected a spray but didn't want to empty the container trying to hit every weed so just delivered it with a slight wiggle. I just did the same for the entire perimeter of the house yesterday so will see at some point whether it kills only what I hit or what is growing close by, but zero spray.

I hear what you are saying and expected what you described but that isn't what I got.

Bud
 
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Old 06-22-19, 04:13 PM
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Even the back splatter from a single stream spray and go a good distance and be enough to kill.
 
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Old 06-22-19, 06:28 PM
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Several years ago, I wondered the same thing. I phoned Monsanto, and easily got through to a representative. She told me that Roundup does expire. I believe she said shelf life was 4 years.

Now I see on their web page that ready-to-use Roundup does indeed have a 4 year shelf life. Click on Product Specs. Couldn't find anything about the concentrate, so you might want to phone and ask.
 
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Old 06-23-19, 05:15 AM
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If you want to avoid the runoff that kills surrounding area try using the Spectrice brand. I switched and now my patio is void of weeds on the patio but healthy grass at the borders.
 
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Old 06-24-19, 06:03 AM
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Couldn't find anything about the concentrate...

Couple weeks ago I used mine, 16 oz concentrate that is at least 2 or probably closer to 3 decades old, weeds are dead. Only thing is don't let it freeze.
 
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