My brugmansias get flower buds and they get to be pretty far along and then the plant throws them before opening. I had a Wreckless Mess with 36 buds on her and within a week had thrown all but one. I have had a few others do the same thing. What causes this and how do I rectify it?
This happens typically due to uneven watering, especially if they are in containers. Brugs are water hogs and in containers, they tend to use up the water available quickly, which leaves them too dry a bit later in the day. This stress can cause them to lose blooms.. Try increasing the frequency of your watering.
If you feel the water is enough, you may have a thrip infestation. These are tiny insects that attack the base of flowers and will cause the flowers to drop before they open. They are so small that they are often difficult to detect. They can be treated with a standard pesticide.