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

Depends on the weed killer for specifics, some are non selective and kill any plant they contact. Like Roundup prevents the plants from making the amino acids it needs. And will kill almost any plant.

Selective herbicides that you might use on a lawn are selective broad leaf killers and generally don’t harm grasses. And they generally disrupt the ability to create proteins that grasses don’t make.