I'd say it's a weed, I'd pull it out before it seeds everywhere.

Verbascum ?chaixii, the native Mullein. Can be a bit of a seed weed, but the favourite food of the now rare Mullein moth. Let it flower then chop it down before the seeds are formed.

It is Verbascum, one of the British native plants. I love them. their behaviour is like a native foxglove. cant tell exactly which one with out looking closely at the leaves. I actually grow it deliberately.

It's great mullein, verbascum thapsus. Lovely, isn't it. Look for holes developing in the leaves, and then try and spot the mullein moth caterpillar as Owdboggy says. They're white with black and yellow spots and get quite big ultimately. The moth is a rather dull despite it's larval stage

I've got one - seeds from another Goyer - and I love it.

It wont be thapsus as the leaves aren't woolly.

Oh, I thought they looked woolly at the top. I know Thapsus is normally very well clothed in a blanket and thought this might have been a moulting one! It's ever so big for any of the others. Dark mullein normally only gets to 5ft or so max. Hybrid vigour? It is impressive, whatever!

That is why I put a question mark in front of the name. We have one very similar which appears in different parts of the garden every year, as well as the woolly leafed one.

You could practically put a tree house in it!

They are impressive , aren't they , Worthy ?
Someone on here last year mentioned that they (in folk-law ) are supposed to keep witches away .

they tend to grow bigger in our gardens than in the wild. I suspect there is a lot more nutrients in our gardens :o)

Hurray, they work - we have never had any witches. I thought it was because of the elder...

or the Rowan?

Elder or mullein, ye witches beware!
Our plants are in place to give you a scare
You'll shrivel and die, curl up with a scream
Ousted by those on the Grows on You team

It's proven to work as Steragram shows
By her witch-free garden where everything grows.
So I say (within reason) power to all weeds,
And let Mother Nature sow freely her seeds

I haven't visited Stera's garden yet , mind you !

You're welcome Driad but prepare to be disappointed! I don't always practice what I preach - getting a bit long in the tooth. But when you make lots of mistakes you learn lots of remedies!
The only rowan is next door Owdboggy, and nearly dead, but it probably contributed.