Hi I had a beautiful pot of sweet williams growing... but due to admittedly lack of regular watering and care, a lot of the leaves had begun to dry at the edges and had started showing the signs of going spindly. As I could see new off shoots coming out from across the lower parts of the stems, and also because the dried leaves were making for an eyesore, I pruned the plant down to quite a bit. As a result, I have now begun to get very vigorous foliage growth - the leaves have become longer and fresher looking than what they were earlier... but no flowering... attaching a photo of what it looks like now... Have I killed the flowering? Or is it still a matter of waiting? My Sweet William ( photo / image / picture from swmitra's Garden )
Did you buy the plant ready for flowering or did you sow it yourself in spring? They usually won't bloom during their first year. If the plant got too stressed it might not bloom for you this year. In my experience (or climate) they are short-lived but good at self-seeding.
Droopy is right. these are a biennial flower. foliage growth the first year and blooms the second year. If this is the second year give it time, it should flower fine for you. If it flowers late, it may not have time to set seed for you if you were planning on that, though. So for next year you'll need to start with a new plant for your flowerbed if it flowers this year.
Why not try to take a few cuttings, tips or side shoots will take very well at this time of the year.