Forget me not. Self seeding thug of an annual/short lived perennial. Dead head unless you want a few million of them.

Yes they are forget me nots and as Owd says they are free seeders and they can take over. if you like them leave a few, but remove the spent flowers as soon as they finish. However the last flower usually opens just as the first flower to open has seeds ready. So be ruthless when there is less than 25% of flowers left remove them.

Many thanks. Happy for them. To reseed like mad as lots of bare soil to cover!