Looks like Digitalis purpurea, the foxglove, to me. Seeds are like dust and can be scattered by the wind. If left you could have them in your garden forever.

it looks more like Verbascum possibly phoeniceum or similar. I have them in the garden. They do self seed but not that freely and take 2 yrs to flower for me. The wavy leaf edge is the same as mine.

Looks like a Verbascum to me too.

Thank you all. After a search I also decided it was a Verbascum. Then I remembered! Before lockdown I planted one in that area where it flowered once then never showed it’s head again. That’s at least three years. I just thought it had died. So, I shall leave it and see what happens this year.

This is such a friendly and helpful website, I’m so glad I joined.

Thanks again.

You are lucky. When I had a self seeded one it was yellow and so, unsurprisingly, were its children.

I think it might have grown from a seed of the one you planted 3 years ago. I think they are biennial, growing 1st year & flowering the next.

Didn’t know that Feverfew. That would account for the delay though.
Thanks everybody. Most helpful.