it is a native Verbascum and it will produce a flower spike 4-8ft tall with pale/primrose yellow flowers.
an important plant for moths.

Wow!! I do remember now putting a teeny tiny plant in last year, yellow flowers I think, wow it's huge! I think it's grown a foot since yesterday! Many thanks for clearing that up

If you don't cut it down when its finished it will probably self seed next year. Mine does anyway.
Eileen, day moths or night ones?

Mullein moths feed on Verbascum. They are mostly night flyers. The leave the plant in a sorry looking sate, but it does recover once the caterpillars have gone. We always grew this just for the moths as they are getting rather rare.

Both moths bees and butterflies will feed on it at all times of the day/night. Mullein moths that lay their eggs on it for the caterpillars to feed on are night fliers as Owd says.

This Verbascum [mullien] will die after it has flowered and it will produce 100's of seeds.

May I butt in again? Do the caterpillars make roundish holes in the body of the leaf ?

they do Yorks. when ready they fall to the soil and pupate in the ground.

Thanks E.