I don't actually have any yellow plants in my garden. I bought it on impulse and it may go to another's garden as theirs is just paving and gravel at the mo - they've just moved house.
I don't like its yellow flowers very much, so tried to eliminate the hypericum in the garden that went with our 'new' house.
That was 26 years ago. I still have to have to yank out regrowths every spring; clearly coming from bits of root I left behind. So it's tough stuff and a bit of a thug
I've planted these lovely plants in many gardens and they seem to thrive in any conditions. They self seed and romp away...your problem might be pulling them up all over your garden in a few years time.
I picked up a bare root in Poundland today and just going to put in pot to start it off. First time I've had one. Looking at the packaging I see at least 23 languages on the side, which made me think how far these go around Europe. Hope it flourishes.