I heard quite some time ago that vinegar, full-strength, can be used as a weed killer. I finally decided to try it on the weeds that are taking over our otherwise dormant vegetable garden. I'm planning to start planting the cooler weather vegetables next week, so the weeds had to go before preparing the soil this weekend. I poured vinegar into a spray bottle and sprayed right onto the weeds, enough to wet the weed and soak the ground/roots a little.
Result? Weeds brown and dead within 24 hours!!
We tried it on some dandelions as well, but it killed the surrounding grass. So only use it where you want to kill all vegetation or where there's no grass.
I also read that vinegar will decrease the pH of the soil somewhat, but within 48 hours the pH balance is back to its original state. So I guess it should be used at least 48 hours before planting anything in that same area.
I'm happy to find such an easy, effective, non-chemical way to kill weeds!