Does glyphosate have a shelf life?

Ultradog MN · Aug 1, 2023

I bought a 2 gal jug of 41% glyphosate about 3 years ago. Used about 3 quarts to burn off my deer plots. It worked good.
The rest has been the basement since - cap screwed tight on the jug, cool, dark location. Never frozen.
I mixed some on Sunday to kill some weeds and brush around here. Used about 2-3 oz per gallon.
So far it has had zero effect.
Thinking about it, I did not shake the jug to remix the contents. Should I have?
Does the stuff go bad or lose its efficacy?

HFJ · Aug 1, 2023

i've got some that's gotta be at least 8 years old. worked last year, i haven't used any yet this year.

i don't know if shaking it up helps, but i can't see where it would hurt.

Dean · Aug 1, 2023

I buy such things when local stores have big sales and sometimes keep for years.

Everything working so far.

I always shake liquids before mixing and shake hand sprayer before using contents.

RM-MN · Aug 1, 2023

Expect it to take 2 to 3 weeks for glyphosate to show damage to the weeds. You're rushing it.

Richard G. · Aug 1, 2023

I use 2 oz/gal of the 41% and it takes at least a week to see any results.
Used some 2 weeks ago that is about 5 years old.
No problems.

rrlund · Aug 1, 2023

I don't know what weeds you sprayed, but this time of year, unless it's new growth, plants are nearing maturity and are putting their energy toward seed production and translocation slows down, so ya, give it time.

BradCNY · Aug 1, 2023

Yes shake it to mix it up. But it is slow to kill vegetation, especially in the summer, 2-4 weeks. If you apply it again mix a cup per gallon of ammonium sulfate in the spray, it dramatically improves the performance of roundup and is needed if you have hard water.

caterpillar guy · Aug 1, 2023

Round up is slow to act at anytime I find I have to wait about a week for it to show. Liberty on the other hand will show in about a day or 2 depending on the weed and size. Lambsquarter will show the tips curling in a day most times. Even 4 foot tall. Ragweed will die fast.Pigweed is slower to show effect. Button weeds wilt in a couple days and shows curling leaves in about 3-5 days. I use roundup and 24D on fenc rows and tree limbs at a rate of pint per 10 gallon same as I mix for beans or corn. 24d a bit stouter. about 16-32 ozs per 10 gallon sprayer full. depends on the age of the 24d and the item spraying. Tough broad leaves and fencerows more and along fields in lighter weeds less.

Steve in VA · Aug 1, 2023

Yes, it does have a shelf life but I haven't determined what it is. I used some that is 8 years old stored in unheated uncooked shop and it worked just fine. At 3 years I don't believe you have any concern.

NY 986 · Aug 1, 2023

I've got generic glyphosate that is 3 years old and I applied some to a field just last Friday. Went back yesterday to check on progress and weeds are yellow and wilting. Ammonium sulfate is recommended as an additive and if tough weeds such as lambsquarters then crop oil as well.

504 · Aug 1, 2023

Slow growing weeds this time of year are slower to kill

paul · Aug 1, 2023

There are several different formulations. Basically sort of different types of salts and additives to process it some is weaker some is stronger in the jug.

Also that makes some types want to settle easier. So you want to do a good job shaking it up if it sat. Lay the jug on its side in the ITV and go for a ride if nothing else...

Glyphosate is slow acting, and even slower if it is dry or real hot or if the weeds are setting seed instead of active growth stage. So you might see very slow results this time of year.

Paul

Geo-TH,In · Aug 1, 2023

I mixed mine at 2% and it takes a long while to work.

You might see tire tracks in the grass because I wanted to use all my mixture in the tank,so I hit the worst places 2 or 3 times. The tires on the lawn mower and the tank sprayer must have had glyphosate on them.

I think mixed glyphosate may have a shelf life, so I use all mixed glyphosate and start out next time with a fresh mixture.

JD Dave · Aug 1, 2023

Which Sunday? Last Sunday or 10 days ago? Allow a full week to see results. The formula for glyphosate is practically end-date proof. It's nothing more than some chemical salts in an aqueous and soluable solution. I've had 4 year-old Round-Up on the shelf and it stills works fine. Use at least a 2% mixture especially if you're treating perennials. For perennials and things like nut-sedge, treatment later towards Fall will be far more effective when the plant is taking nutrients and poison down into the roots.

Ultradog MN · Aug 1, 2023

Great replys fellas.

I've only used this stuff once.
I sprayed an acre+ plot at our property then went back up 2 weeks later so didnt see how fast or slow it died off. It burned off everything then.
Lot of woody/brushy stuff growing up behind the garage here at home including cockle burrs and another tag along burr that is invasive.
Buckthorn too.
I will need to pay more attention to it in the future.
Attack it mechanically and chemically.
Thanks to all.

hd6gtom · Aug 1, 2023

I've had some over 10 years that still works.

RM-MN · Aug 2, 2023

Different weeds respond differently to chemicals and the age of the weed matters too. Your cockleburr will respond to 2,4-D just fine but as they get bigger they are harder to kill. However, spraying them with 2,4-D will prevent them from producing viable seeds even in early August. If the soil is never disturbed, you can kill out cockleburr by spraying 3 times a year for 3 years.

Does glyphosate have a shelf life?

Ultradog MN

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HFJ

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Dean

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RM-MN

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Richard G.

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rrlund

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BradCNY

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caterpillar guy

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Steve in VA

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NY 986

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504

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paul

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Geo-TH,In

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JD Dave

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Ultradog MN

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hd6gtom

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RM-MN

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