In article ,
"Rupert \(W.Yorkshire\)" writes:
|
| The blue one (Echinops ritro) comes every year from the existing rootstock.
| It will self seed and produce additional plants.
| You can chop back the whole plant to ground level at the end of the season.
| I assume the same applies to the white one as the link posted by Janet says
| that it is a perennial.

Both are. They are absolute b*gg*rs to get rid of when you want to,
as they will regrow from deep roots. They probably won't thrive in
heavy clay, but love light loams. I have never found them to self
seed much, but have never grown more than one plant.

I had forgotten that the white one wasn't a variety of E. ritro but
E. sphaerocephalus - plants that you buy as the former may well be
the latter, and it is a much inferior garden plant.


Regards,
Nick Maclaren.