This has appeared in the garden.

Is it a chive?

Too big for a chive, look at it towereing above the nasturtiums. I think it is an allium.

Could be a purple headed leek. I've had the occasional one before but I'm considerably further south than you! (The Algarve)

It's an allium - these small bulbs come up later than the big ones

I've had more of these this year. Plain white but doesn't smell oniony either.

Pretty sure it's an allium bulbs can get dropped by birds too

It is an allium, very similar to the ones I have in flower atm (much later than the larger forms), they set seed and self sow very easily, certainly birds will spread them.I get them popping up all over the garden.
Allium sphaerocephalon

Definitely an allium stansgran I have a collection of around 25 and they look exactly like that ! Wish I knew how to post a photo.

I have a clump of these in my garden - allium sphaerocephalon (I think). I have all sorts of alliums but these are my fsvo

Favourites it should have said!!

It's as Greyduster says, I've got them too!

Yes grey is right. It is what she says. On the way to Hampton Court one year there was a roundabout with these mixed with -oh blimey senior moment! - those blue flowers on long stems from South Africa - bulbs. Anyway it looked grand.

Thank you all. The bees love it so I might try to collect seeds and encourage it.

I have had this appear.....