

Most powdery mildew fungi have a host range restricted to a relatively few, related plants, but these can include wild relatives which can be sources of infection, e.g. Promptly pruning out infected shoots will reduce subsequent infection. Non-chemical controlĭestroying fallen infected leaves in autumn will reduce the amount of infectious spores next spring.

If chemical controls are used, they should be used only in a minimal and highly targeted manner. The RHS believes that avoiding pests, diseases and weeds by good practice in cultivation methods, cultivar selection, garden hygiene and encouraging or introducing natural enemies, should be the first line of control.

RHS Garden Wisley Flower Show - 5–10 September 2023.RHS Garden Rosemoor Flower Show - 18–20 August 2023.RHS Garden Hyde Hall Flower Show - 2–6 August 2023.RHS Flower Show Tatton Park - 19–23 July 2023.RHS Hampton Court Palace Garden Festival - 4–9 July 2023.
