Mine are justing starting to flower now, you can collect the seed for next year or let them self seed.

No it is an annual doubt any plant you have just bought will flower.

You might be lucky and manage to keep them until next year when they'll flower, but they're not hardy plants. It depends on how sheltered your garden is, and the temps. we get in the winter.

I grew these from seed in Dundee, east coast Scotland. They grew to be huge and gorgeously smelly, flowering July to September. They are an annual but go for the seeds. Stellanash

They get frost damaged even here, so if you want to keep them over the winter, I would put them in a heated greenhouse..

I kept one out of six a couple of years ago...not a good percentage, I know! They certainly wouldn't have survived the last two winters.