Why has my rose Queen of Denmark produced no flowers this yerar

Hi and welcome to GoY...Is it a very old plant,? is it fed and pruned each year?
If you sowed your annuals in the open ground.and.if there was moisture there, they should have germinated. How long have you had the seed?
Sorry to ask so many questions, but it would help to give us an idea of what the problem might be.

And what has the weather been like in Glasgow - unusual at all?

The rose is about 15 years old, is pruned and fed each year.

The weather in Glasgow was particularly cold and dry following sowing of annuals, The seed was new this year.

The rose is a fair age, but it is said they can go on for 25 year! However, it may be that it is "over the hill" and needs replacing?
Your annuals would have need a bit of warmth to germinate but not that much....did you keep them watered?
It may be that you were unlucky.