Philadelphus

I have green leaf one - I don't know what variety it is but it's a thug and never has any issue with scorch. Gets lots of sun.

As a precaution before moving yours you could take some cuttings? I took half a dozen last year and they all took.

Well you are clearly a better gardener then me - have tried and tried - but never get them to go.
dont have much trouble with other stuff - just this one that I would like to hang on to!

Maybe just lucky? I'm not always that lucky - I often pull them up to check and damage things
I think the trick is timing...and just being left somewhere. Though I always find the fancier the variety the harder to grow or propagate.
I love sedum - the green one is prolific here - I bought a black ( or very nearly) it's not done that wel at all.