Weed control is a struggle shared by all gardeners. Hoeing and pulling weeds works, if you have the energy and time. Other organic methods of ridding your lawn and garden of weeds are safe and effective when used properly. Organic methods are non-selective, so you must use them carefully, and only on plants you want to kill. They will kill anything they contact--desirable plants as well as weeds.
Pour boiling water on the weed and it will produce almost instant death. Boiling water will also kill any “good” plants it touches, and the steam may harm nearby plants. Boiling water kills microorganisms in the soil as well.
Burning weeds with a torch device is another instant kill. Burning large stubborn weeds is one way to permanently eliminate them. This method is somewhat easier to control than boiling water, but it has drawbacks. Torching can cause discoloration of stones and sidewalks, and it may alter other paving materials. It leaves behind blackened plant debris that may remain unsightly for two weeks or more.
Ordinary kitchen vinegar has acidity of 5 percent, while organic herbicidal vinegar is prepared at strengths of 10 or 20 percent for quick knockdown. Increase the acidity of home vinegar by boiling it down to half volume, and the strength will be 10 percent. Spray the vinegar onto plants you want to kill, and it works within one or two days. Vinegar kills any plant it touches.
Any kind of salt acts on plant cells by drawing the water out of them, which kills the plant. Regular table salt can be sprinkled on a weed. A pinch of salt placed at the base of the plant will kill it, or a solution of salt dissolved in water can be sprayed on the weed. No matter how salt is used, it has a long-lasting effect in the soil, and it may be years before anything will grow in the salted spot again. This may be desirable for weeds in a gravel driveway, but remember that salty runoff can ruin the soil at the edge of the driveway.
Rubbing alcohol, or any alcohol, causes moisture loss from the plant cells. Spray it on weeds, or dab or paint it on. Deep-rooted plants like dandelion may need more than one application.
Corn gluten is a pre-emergent inhibitor, and not a true weed killer. It does not kill growing weeds, but if you sprinkle it on the ground before weeds have sprouted, corn gluten will prevent weed seeds from germinating. Corn meal is the whole grain corn, so it contains gluten. Corn gluten is light and powdery, and is available at garden centers with the rest of the whole grain meal removed. A bonus to using corn gluten is that it has a fertilizer nutrient NPK ratio of 9-1-0, which makes it an excellent organic weed-and-feed product for lawns.