It is the wild, field version of the Forget-me-Not. Pretty but it can quickly get out of hand.

Ah, thanks very much, Bulbaholic. It is confined to a smaller area this year, but it was going crazy last year. I have no idea where it came from.

Bird dropped seed very likely

I was wondering if it was in a hanging basket? I often use packs of varied plants to fill the baskets and wonder if that was in there one year.

Shouldn't have been given it is a wild flower but, who knows!

If you don't want lots and lots more next season it's as well to take it out before it sets much seed.

Thanks, Steragram. I will do that as it is a bit of a problem growing around the other plant.

You may be bit late this year but nothing venture nothing gain.

I wheeched them out anyhoo. Next year, I can watch for them and try to keep on top of it.

Wheeched - wow a new verb to remember! I like it. I've been wheeching out grass this afternoon.