Solved what is this plant that I planted?

Last year (early summer) I planted this perennial in the corner of my raised bed. I thought it was a campanula but it clearly wasn't! Two weeks ago it was about five foot tall. It didn't flower last year, died away over winter and reappeared this year. Since my pictures were taken two weeks ago, it appears that small yellowish flower buds are forming in the spaces between leaves and stalks and in the past two weeks, the tallest stalk has grown so long that it has dropped down to the patio and is growing along and bending up. What on earth can this plant be?

 

Perhaps it is a Mullien?

Verbascum thapsus - Wikipedia

 

Not Mullein.

Maybe Balsam?

 

Interesting.
Biennial possibly?
Extremely square stems.
Do please add pics to this thread when the flowers open.

 

Maybe one of the Physostegias ?

 

This is my balsam. Just had a thunderstorm so the flowers took a beating. Grown from seed this year

 

I hit post too quickly. I was trying to agree that the serrated edges of your plant are the same as my balsam. This is the first time I tried growing or even having it. I don't think it would be anything but an annual given our harsh winters.

I like the flowers.At first I thought they looked like snap dragons. And I like them too

 

Well, after a month of flower buds growing slowly on the stalks, a couple of flowers have now finally appeared! Nothing like this happened last year. Hopefully this picture help you experts identify the plant conclusively!

 

Excellent. Thank you for new pics.
That helps.
Campanula sp.

 

Campanula Persicifolia Alba? Buy peach-leaved bellflower Campanula persicifolia var. 'alba'

Mr Googlr can't find a good picture of the leaves but the flowers look right:

 

Have a look at Campanula Pyramidalis. The flowers aren't right for C. Persicifolia. Pyramidalis are star shaped like yours, C. Persicifolia are bell shaped.

 

Thanks guys, at least my memory didn't let me down, it WAS a campanula!!! Just not like the campanula elsewhere in my garden, which is is purplish and covers the borders. I've not seen a giant one like this before. It will be a talking point for all my visitors. Case solved.