 
The most likely cause is a fungus called petal blight, which only affects the flowers. Collect and dispose of all flowers and petals, also any dead flower buds remaining on the plant. Sprays of Systhane Fungus Fighter Plus from Bayer or Uncle Tom's Rose Tonic after flowering may help to reduce the problem for next year.
| 
 Gardening Expert:  | 
If you can't find what you are looking for on the website then you can ask one of our experts. To get in touch with us Click Here
We will try to get back to you with an answer as soon as we can.
Did you find this answer useful? Subscribe to our newsletter for gardeing news, projects, special offers and competitions.
Eram Garden
Shiraz, Iran
Pukekura Park 
New Plymouth, New Zealand
Medellin Botanical Garden
Medellin, Columbia
Pamplemousses Botanical Garden
Pamplemousses, Mauritius
Monet's Garden, Giverny
Giverny, France
Majorelle Garden
Marrakesh, Morocco