The bush is some 10 years old and nice and healthy except for this problem.
10 October 2011 11:24 PM
It is most likely an environmental problem that is causing the flower buds not to open. Ensure that your plants have protection from the hot sun and have adequate moisture available to them. If an abundance of buds have been formed in Spring, it may pay to remove a number of them and then fertilise with a fertiliser such as Yates Thrive Natural Roses & Flowers Pelletised Plant Food. It's enriched with Dynamic Lifter and has added nitrogen, phosphorus and potassium to give your flowering plants the right balance of nutrients for their growing needs. . This will ensure that the plant receives sufficient nutrients and hopefully encourage the buds to open.