Edibles and poisonous plants growing together

[iko.]

Hi,

This is my first post here after a few days browsing the useful messages you all have written.

I hope this will not sound too naïf but, is it dangerous to grow edible plants in a root-bound pot of Nerium oleander, Euphorbia ingens or other poisonous plants? I am curious to know if a tomato or basil growing close can end up getting some of the nastier properties of the other plant. I have searched for an answer on this a few times but nothing clear comes up. Some of you will be thinking of the ToMacco from The Simpsons when Homer creates a tomato and tobacco cross and then he fertilises with plutonium. If anyone is curious, some else tried to replicate the idea, see here.

Spoiler: I am not planning to create a new monster plant but I want to grow some edible plants in a garden with some really big Euphorbias and one oleander impossible to kill. The space is limited and every time I dig a bit I can only see roots of these plants.

[Tropicaltoba]

I think the issues with euphorbias is the caustic sap. I grow marginata in my native wildlife garden and the birds eat all the berries of the surrounding shrubs without ill effects. It is one plant that never gets deer/rabbit damage.  My concern would be that if I’m hunting around for fruits I may not be aware that the euphorbias could be damaged and I may come in contact with the sap and not know it until much later.