Potentilla problems

I've grown Potentilla Atrosanguinea 'Fireball Mixed' from seed for the first time this year.

I started them mid February and they went out into the garden early May. They are now showing sizeable clumps of healthy green foliage but absolutely no sign of any flowers or buds.

Is this typical? am I doing something wrong? They are listed as hardy perennials - do you think if I leave them in overwinter they will grow back next year and flower then? has anyone had the experience of them only flowering on their second year?

I'd appreciate any advice.

 

Thanks so much for that info Marley. I guess I'm going to have to be patient a bit longer! I planted them because I heard they had good slug and snail resistance and so far it's proving to be true!