Botrytis is transmitted when the light intensity is low and the humidity high.
- Black or brown spots on petals.
- Die back of soft stems.
- Die back from wounds caused by harvesting or pruning.
Do not harvest rose stems more than a centimetre above an eye (die back will occur if harvested too high above an eye).
Do not prune if the growth medium is wet.
Spray with fungicides registered for Botrytis on roses (spray in the morning).
Do not spray fungicides or water on the flowers during the afternoon.
Do not irrigate from above when it is cloudy and cool.
Buy our rose CD and use our user friendly key for the identification and treatment of pests and diseases in your rose garden.