Non-flowering Heleniums?

[CogitoErgoSometimes]

Planted six in a sunny border back in March, watered well, and they're all looking big and healthy with plenty of new growth. But only one has flowered. Any ideas?

I planted a 'bare root' one and it took one year to flower and has now spread beautifully. They flower quite late in the season though. Maybe the weather?

You're probably right. Maybe I just have to be patient and they'll do their stuff in Year II. Got them all at the same time as smallish plants and put them all in the same spot with identical conditions so couldn't work out why just one is flowering.

Thanks