Devon,
United Kingdom 
I bought 12 verbascum this year from three different sellers. Having given three to a neighbour, and none of them are getting bigger, I'm wondering whether they are all biennials
1 Jul, 2021
Answers
Depends on which species. many are biennial though some are short lived perennials and should flower for 3-4 years before dying
2 Jul, 2021
Not annuals anyway...
2 Jul, 2021
The leaf rosettes should gradually become bigger, though.
4 Jul, 2021
Thankyou all. I've realised now that the ones I bought are indeed a biennial. I've got some that come up every year and for longer than 5 years, so I'm ready to lose them next year. Thankyou for that info.
4 Jul, 2021
You get a little clump of leaves the first year and a tall flower spike the second - so yes, biennial.
1 Jul, 2021