Q.How to Kill Plumbago
My parent in-laws bought a plumbago and it is growing over and killing off their much loved conifer plant, in the garden. How do we kill the plumbago without killing what is left of their Conifer? I don’t have any photos sorry.

Certified GKH Gardening Expert
The best way to do this would be removing the tree by hand anytime that it sprouts up. Another option would be to pour boiling water ONLY on that tree and the stump. Mechanical removal will be the best option, but as long as you don't get the hot water on the conifer, than this can help.