“I have a beautiful pink rose bush, but the flowers are starting to look like they are dying as soon as they open. What can I do?” Question from April of Dresden, Tennessee
Answer: I bet you have had a cool, wet spring because this is when rosebud problems appear. Climatic changes can roses to turn brown on the stem, but fungal disease is the most common cause. In general, the common name for this phenomena is called rose balling.
Climatic Causes for Rose Balling
If your flower buds looked normal, but then developed dry, papery outer petals and healthy looking inner petals, the cause could be due to a physiological response to weather changes. When weather is rainy and cool and then is quickly followed by hot, sunny weather, the water-saturated outer petals can fuse to one another and dry on the outside–disabling the flowers from opening normally.
Fungal Causes for Rose Balling
Fungal rose browning/rot is caused by Botrytis Blight (Botrytis cinerea). In most severe cases, the buds will turn brown before opening. You may even see signs of grey mold on them. In less severe circumstances, the flowers will open with brown petals or brown patches on the petals. This is most likely your problem, especially if your weather has been consistently cool and moist and you see signs of mold.
Managing Botrytis Blight in Roses
Here are three easy, all-natural steps to managing botrytis blight in roses.
- Remove all dead or dying flower buds, being sure to remove all the brown parts. This will reduce the spread of the disease. Be sure to sterilize your pruners after cutting any diseased plants. Dipping them in a 10% bleach solution works.
- Increase airflow via pruning. Dense bushes with too much foliage can encourage fungal disease by discouraging air flow. By selectively removing overgrown branches or young suckers, you can really reduce fungal disease problems on your roses.
- Use liquid copper fungicide sprays, which are OMRI Listed for organic gardening. These are safe to use and will help prevent further rosebud attacks.
I hope that this helps!
Happy rose growing,
Black Gold Horticulturist