what we really need to do is instill the lesson to never eat plants unless you know they are safe.
This reminds me of the time when one of my BiLs was commenting on our locking drawers and using a stair gate. His approach was to clearly explain to his daughter that certain drawers were dangerous and she wasn't allowed to open them. Likewise the stairs were only to be used with an adult.
That's cool if your kid listens, rather than ignoring you and smashing anything with a handle open and closed like a madman. Or running off and climbing the stairs whenever they can.
To be fair too them, they're very good with the plants and generally only eat the herbs - and if you provide a bowl of water will wash them. However, when they were ~1yo they just started eating a weed and randomly one day. They're 2+ now and very recently while I was pulling out bind weed they just started eating it. This is despite absolutely knowing only to eat herbs. They were simply adamant you could eat it.
Ultimately your impulse control isn't fully developed until your in your 20s, and it's almost totally absent from small children. Plus I dare say folks here don't remember all the times when they were small and a supervising adult was watching over them while reminding them not to eat stuff.
So while I wouldn't take anything out that's there, I definitely would not add dangerous plants.