Linum? Flax

No its Phacelia. it is a quick growing hardy annual used as a green manure. It is an excellent bee plant.

+1 for phacelia

Many thanks for that. I had never heard of Phacelia before and I'm pretty ceratin it will be news to the rest of the group. It looked pretty spectacular to see so much of it. We had already dismissed that it might be Flax, which has a lighter blue, though the photo doesn't show that too well. I'll let them know. Thanks again.

I grew it about 10 yrs ago to encourage bees and I still get the odd one poking through, seeds freely.

I got an odd one in the garden some years ago and it took ages to find out what it was - even the chap at our local nursery didn't know.