Sambucus black lace
I’m not convinced this is a suitable plant for a pot
It wants to be a really big shrub / small tree. I cut mine back to about 2 - 3 foot high every spring and still need to trim it mid season to keep it at about 2.5 metres high.
Heaven is ... sitting in the garden with a G&T and a cat while watching the sun go down
It's good to know that it can be pruned after it flowers........I actually forgot that it flowered until I saw one last year. I pruned roughly one third of it this Spring, and was happy to get flowers this year.
Take out all dead branches to give more light.