They need to build up the flower bud this year, for next year's flower. They must be in a sunny open position and don't like to be shaded by trees/ other plants etc. Feed them once a week for the next few weeks. The top growth will die down for winter so mark where they are so that you don't accidentally spear them with a spade!

I tried them and had the same problem of not flowering. I think they need room, as mentioned above, to spread the roots undisturbed and sunshine on them. They were magnificent at Hyde Hall RHS garden, until they replanted the old rosebed they were in, they just seem to have disapeared now. They bloomed so well and self seeded. A lovely plant, but very fussy over siting and not being disturbed.

They are originally from the cold deserts of central Asia and meadows in the Himalayas, so they will need lots of sun, good drainage, and light feeding while in leaf. Another consideration is that they not be planted too deep. That will correct itself, but it may take several years.