Euphorbia amygdaloides-invasive?

I've just bought a lovely euphorbia amygdaloides purpurea for my garden.

I have heard they can be quite invasive and dominate the ground and plants around them.

Is this true?

In that case would I be ok to plant it like i do mint? I.E. in a large pot with its base cut out buried in the ground -to stop it spreading?

Or is it a slow grower and easily controllable in the ground with a bit of effort?

It certainly spreads gillettemancs but if you find it invasive it is quite an easy shrub to thin out - it just lifts up, you don't need a spade or anything although if you wanted to make sure you had it all out it might be a good idea to dig round it but if you just wanted to thin it out its not difficult. It grows so easily perhaps a pot would be a good idea. It is lovely though.  There are some euphorbias that are invasive, ie a small fuzzy looking one - bright greeny yellow but I don't know it's name - it brightens up the garden for sure but it definitely knows how to spread - wildfire springs to mind.  Wait for an expert though because I'm not great with names and can only say what they do in my garden.

Lavandem, I have a fens ruby growing.

I had a little clump I moved from one country to another. It behaved itself so well for the first three years, and I loved it so much, that I split the clump and moved to another border. It obviously enjoyed the new location so much so, that it is walking around the garden borders. But I don't mind it walking about as it deters the mole. He just sticks to the grass. (Not lawn, but short paddock grass) so not worried.

That's interesting Backyardee as this is my 3rd year having it in my garden and I'd love for it to spread, so far it has grown in size but not self seeded or spread. I don't have much bare soil around 'tho. Hopefully this year it will start wandering.