I don’t know where you live, but I’m in PA, and I trim Annabelle Hydrangeas on Valentines Day. They are indestructible around here, and I dig up some every year for friends.

I found a video. Hope this helps.

https://m.youtube.com/watch?v=nOV8BRLAS1Y

In northern VA, hydrangeas are among the last shrubs to leaf out. I wait until late April to prune out the dead wood - that's the only pruning that I do.