In article .com,
Clifford writes
Chris,
I have a Valerian plant in my bog garden. The rest of the garden is
very sandy and free draining. This year I have had seedlings appear
everywhere, in plant pots with my bay tree, in the strawberry bed, even
amongst my overwintered perennials in pots.

Is Valerian officinalis? I guessed the OP was talking about Centranthus
ruber because he was talking about the fluffy seedheads. I can't
remember what the seeds of Valerian officinalis are like - are they
fluffy too?

--
Kay
"Do not insult the crocodile until you have crossed the river"