Organic herbicides that kill weeds in a lawn can harm grass too, so read labels carefully. Most are sold in spray bottles to make them easier to use and control. Some natural weed killers are: Corn gluten is an organic herbicide that stops specific weeds from growing roots. It is used to control crabgrass and some other lawn weeds before they grow. Acetic acid or horticultural white vinegar kills weeds naturally and fast. It only kills the part of the weed it touches. Wear safety gear and goggles with acetic acid because it can burn your skin.
A flame weeder is a wand connected to a propane tank that lets you target specific weeds. Flaming kills weeds above the ground but not the roots. You may need to reflame an area several times to rid it of weeds. Tip: Avoid using a flame weeder during dry seasons or while in a drought.
Boiling water is a natural way to kill weeds. Heat water to at least 200 degrees and pour directly onto the weeds. This technique of weed prevention may work best with weeds growing in gravel or between paving stones. You may be able to prevent, control or kill certain types of weeds using products around your house such as dish soap, epsom salt or apple cider vinegar. Tip: Be safe. Use a teakettle for boiling, heating and pouring water.