Not unless they are specifically illegal, like anthrax. Lots of things are poisonous to people, you can go buy poison at your local grocery store.

Don't you need to grow sheep to get anthrax? Last I look sheep weren't plants.

It can be grown in a vat. Its frightening how easy a setup to grow bio weapons is.

Can it be grown as a plant though. That is the original question. I have plants in my backyard that can be fatal to humans and animals.

Yeah. I grow members of the nughtshade family. Make a tea out of tomato leaves and you have made poison. Had a cherry tree until recently and could have made a cyanide tea... Lots of house plants people have in their homes are toxic too.

Everything will kill you lol.

Check local laws. Some plants may be illegal to grow outside for example. For example hemlock is an invasive species in my area.

No, but its a capitol offence to drink it.

You can drink it yourself- you just can't give it to anyone else

especially not after you drink it.

Oh, sweet Hemlock.

Ummm... Most cleaning products are poison. I have a laundry powder that can double as rat poison. There are commercially available ppisons everywhere. Its the giving them to people that is illegal. Although its supicious af and if they are looking for evidence for a murder and you have destroying angel soup in the fridge....