Geoffrey Porter asked 12 years ago
My rose bush’s new leaves have what looks like a white powder on them. See attached picture. Can you please advise what this is and how I might correct it?
1 Answers
Gerry Daly Staff answered 6 years ago
This is rose mildew disease, which disfigures and weakens the bush.
It looks like the rose is growing by a wall and the soil would be dry and this encourages mildew, as does too rich feeding and too much organic material.
Water the rose in a dry time and increase potash feeding to harden the growth.
It is likely that spraying with a rose fungicide such as Roseclear or Multirose will be needed. While this is not essential, considerable disfigurement of the foliage and reduced flowering will result without spraying.
