powdery mildew on my akebia vine on leaves and growing shoots

by cath beetham
(Devon . England)

Every year after a vigorous start and after flowering my akebia vine gets attacked by mildew and leaves drop off. I have tried spraying sachets of fungistat every two weeks as the box suggested but notheing seems to cure it. How can I treat it?

Doug says Try a search or read this basic article for starting points