What Is the Strongest Weed Killer?

The strongest weed killer is sodium chlorate, produced in dust, spray and granule forms. When used as an herbicide, sodium chlorate is toxic to green plants and kills them when it is absorbed through the roots or through leaves and stems.

As this chemical makes the surrounding soil sterile, it is used mainly in non-crop areas to control vegetation around roadsides, fences and ditches. Sodium chlorate is toxic if ingested by humans and can be explosive if mixed with other substances, such as sugar. Commercially available chlorate weed killers contain approximately 50 percent sodium chlorate mixed with a fire suppressant. Its use as a weed killer is banned in the European Union.