Weeds are frustrating nuisances, whether in the yard, garden or between cracks in sidewalk concrete or driveway asphalt. Cutting the weeds is a short-term solution because they grow back from their roots. While bleach will kill weeds, it is not an ideal solution.
Bleach contains compounds called surfactants, which help the bleach to deeply penetrate organic tissue. This lets bleach do damage to the inside and outside of a weed's leaves and roots. If bleach penetrates the ground and reaches the roots, the weed will die.
If bleach is poured onto the soil, all plants that come in contact with it will die. Large amounts of bleach can leach into water supplies. Children or pets could be harmed if they play in bleach-contaminated soil or plants.
Pour vinegar or boiling water on weeds as an alternative to bleach. For large patches of weeds, spread thick plastic sheeting over the affected area for about 10 days. Without sunlight, water or air circulation, the weeds will die.