Hello, I live in Zone 6a and there are amazing Annabelle Hydrangeas all around my neighborhood. They are in full bloom right now, but mine, alas, is sad. Instead of snowball-like blooms, I only have a few small flowers in bloom. I have tried watering generously, I trim off the dead wood in the spring, I have been fertilizing with phosphorus weekly (Miracle Gro Flower Food). This is at least my fourth year with this sad plant, and I am thinking of ripping it out if I can't get some better results.

I think you have the wrong type of hydrangea. Annabelle is a hydrangea arborescens that produces mophead form blooms. The shrub in the picture resembles a wild hydrangea arborescens with lacecap form blooms. The center of the blooms consists of fertile flowers surrounded by white sepals sprinkled here and there on the periphery.

Thanks, Luis! Looking at photos of wild hydrangeas, I think you are right. Whatever nursery I bought this from mislabeled it as an Annabelle.

They probably labeled it without blooms open. The majority of those hydrangea arborescens have lacecap form blooms but their mophead cultivars usually have the same foliage.