I actually tried to grow Sweet William last year. I sowed the seed, the plant came up and grew quite well but never flowered. It then didn’t die back over Winter. So I left it in the ground, through all the snow and frost and wet. Then in early Spring it started to grow again and now I have row upon row of beautiful flowers, poised to open at the first sign of sun.
On further reading I found that if you plant from seed in year one then you will actually get flowers in year two. Doh! should have realised that last year. But in any case I’m delighted with my raft of free cut flowers. Expect Sweet William in every room in the house very soon!