How do weed killers just kill the weeds and not surrounding plants, flowers and grass?

Question

How do weed killers just kill the weeds and not surrounding plants, flowers and grass?

In: Chemistry

Answer 1

Common weeds tend to grow a lot faster than common garden plants. This means they suck up a lot more water and “stuff” from the environment.

Many weed killers will actually kill any plant **but** they degrade into harmless chemicals fairly rapidly. This means that your grass doesn’t have time to absorb enough to be harmed but weeds have pigged out on it and will die before the weed killer becomes inactive.