Regular feeding.

And watering, and I think packing the plants in tight......

I do feed regular and water hence my username perhaps I should apply the same to my plants thanks anyway.

Could you ask your council what they do to have such thriving plants? It is a mystery isn't it? I work in town and so am around quite a lot but I never see gardeners tending the annuals. Perhaps they do it at night??

Yes, they pack them in tight... An abundance of plants = an abundance of blooms.

And I have seen the council contractors go around at night watering and feeding. The packing them in tight is interesting though. Might be worth a try next year or with pansies and violas coming up. ummm !