Bud drop is a very common problem in Florida and, judging by the number of postings I see here about it, I think it must be a problem everywhere.

There is a tiny insect that burrows into the buds and sucks the juices from the stem end. Everything looks fine one day and the next you have perfectly formed and still green little buds littering the ground under the shrub. Sometimes they stay on long enough to go yellow but not always.

If you snip a few buds off a couple inches below the stem end and put them in a tightly sealed zip lock bag, you should see teeny wormy critters by the next morning.

The only solution that I've found is to dust the plant, especially the buds, with Sevin dust. It's available in any store's garden section, it's not expensive, and it's effective. It won't look pretty when you first apply it but after a few days it will wash off in the rain and suddenly you'll have flowers! (Sevin is very effective against fleas too - I've known many people who dusted a flea infested yard with it and even used it on their dogs with no apparent ill effect on the animals.)

It's worth a try...

Post again to tell us if it worked for you!

If you use Sevin on or around animals, get the weaker formulation (there are at least two strengths). Read the package, as the stronger one is not recommended for use around animals.