Is this mould on my clematis ?

[cornflowerbluey]

What is this white powdery substance on my clematis? Is it mould and if so what can I do about it ?

Yes, it is actually powdery mildew and you can treat it by spraying with a bottle of water and about 10% milk added to the bottle.

Don't ask me how, but it works.

It's a sign of dryness at the roots so a generous watering will help it recover.

Does this stop buds from flowering? We’ve had similar for the last couple of years, loads of growth. leaves and buds appearing then everything on that stem dies before the flowers appeared. Then get new growth and the same happens. Had about 3 flowers so far this year

No effect on buds so far....

Thanks for that, I'll try your advice.

A spiraea of mine has been really hammered by it this year; it's been there a very long time and never been affected before.