Very probably

Thanks Anchorman, I'll do it. No option really because they are too far gone to start using remedies.

Centaurea are rather prone to mildew and stem collapse.

I cut back lots of my customers plants and almost all flower again within a few weeks

That gives me hope and stops me blaming myself! Thaks again.

I often use twiggy sticks to support them. but at this time of year i do cut them back to get new growth and a late flush of flowers.

Thankyou SBG. I did prop them up but I think the hardy geranium in front of them were crowding the centaurea. Some of my plants are massive this year - too big really.

Hi - Mine have done exactly the same thing and I cut them right back and in less than a week there is masses of new growth and today there are four perfect flowers. The new ones are on much shorter stems but the new growth covers as much ground as before.