Cephalaria gigantea

8 foot tall yellow flowered Scabious thing. Anyone ever tried to dig one out? The roots are like Parsnips on steroids!. BUT, the question is, are they persistent? I mean like Dandelions or Docks and have dormant buds all over them so that any bits left will regrow. Or are they like buttercups where once the crown and all its buds are removed the roots die off?
TIA.

 

I don't know Palustris - but I had a Google.

Looks like an Owdboggy has a similar problem - but I think you know that. :D

I also found this from Sacha at Hill House Nursery

"The other thing we have found extraordinarily stubborn in terms of "we don't
want you just there", is Cephalaria gigantea. Ray decided that a large
clump in one bed was in just the wrong place and thought he had dug it all
out. It returned in precisely the same place the following year but if
anything, more of it! We concluded that it must flourish on unintentional
root cuttings, or something!"

 

Great, thanks. Will just have to wait and see. The way the roots go down I think there is some antipodean person clinging to the other end.