Thank you all.
Grammaretto I think you are right ?
Agree it a lovely plant, hopefully will get some seeds for next year.
It was growing all around farm.
I will ask about the green manure in our next visit.
The farm has gone back to large deep hedges with several feet of wild flowers on either of the hedges to encourage bees and others pollinators, so it quite likely that they could be using green manure.
Hopefully this time next year I will be posting a picture of several phacelia on our garden.
Btw it was my first attempt to post a picture.