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

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

In: Chemistry

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.

There are also some GMO strains that are bred specifically for herbicide resistance! Here’s some info about it!

https://www.beyondpesticides.org/programs/genetic-engineering/herbicide-tolerance

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.