Henbit and vinegar
Five-percent white distilled vinegar from the grocery store will kill henbit, a cool-season annual weed. But I think the vinegar needs to work in conjuction with some other factor to be effective against henbit. That factor might be warmer temps like 60 degrees plus maybe, or perhaps it's a lot of sunlight.
I've been able to kill tons of henbit in my *back*yard with a 5 percent white distilled vinegar spray, but when I sprayed henbit located in my *side* yard that gets much less sun and gets lotsa shade due to the house, the henbit would not die. I sprayed that henbit on the side of the house 2 or 3 times on 2 or 3 different days....sprayed it heavily. I really unloaded that vinegar into the henbit, but the henbit wouldn't die. It looked perfectly fine days later as if vinegar never touched it.
What gives? Does vinegar need to work in conjunction with *sunlight* to eliminate henbit? Or does the vinegar need warmer temps? I finally had to pull out the sideyard henbit to get rid of it.
Tons of henbit got wiped out in the backyard by using vinegar but the usually shaded sideyard henbit still looked strong and untouched. It laughed at vinegar.
I'm not sure what the X Factor is: sunlight or warmer temps.