I think they were late going in, given a bit of flower feed, they will probably flower some time in August.
Dont panic yet.
As fidget says, it's quite late, but mine went in at the end of May/early June as small plants. That's normal for here. It just means you'll have flowers in autumn. Every cloud...
I think plenty of food is necessary, given the amount of plants in a small space. That way, you have a better chance of getting some flowers.
If they're in a very sunny spot, you could also move them where they'll get a little bit more shade - especially in the middle of the day.