It is amazing how fast it works though when the fertilizer company sprays it as a burn down. You should see the winter cover crop they sprayed
The last Roundup I used literally worked over-night.
My daughter was moving, and had it in her garage. It was Roundup PreMix Refill.
Pick up a jug of 1.5 Gallon pre-mixed Roundup Refill,, and read the ingredients.
I can not remember the exact percentages, but, the mix is like 2% glyphosate,, and 2% of some "acid".
I Googled the second ingredient,, is is some adder that makes glyphosate act VERY quickly,,
Everything I sprayed was starting to die the next morning.
I could not find that second ingredient for sale as a separate item,,
And, when I back-calculated the mix, it had 6 ounces of 41% glyphosate per gallon.
I think the normal recommendation is 2 ounces per gallon??
Roundup charges a high price for the pre-mix,, but, they sure have the chemicals in the jug.