Q.clip off spent flowers on rhododendrons
Do you clip off spent flowers on rhododendrons in late spring, but wait to prune the shrub in late fall? I live in northern Westchester County, NY. Not sure what the zone is. I’m reading the advice about when to prune a rhododendron. It seems to conflict. So, is the advice to remove the flowers right after they are spent, but not prune the branches until fall or winter? The variety of rhododendron that I have is the one that produces smaller flowers in the middle of spring. Thanks for any help.

Deadhead the spent blossoms as they fade, though out the blooming period.
Pruning you will clean up the entire plant which needs to be done when the plant is dormant.
I hope that clears it up for you, happy gardening!
https://www.gardeningknowhow.com/ornamental/shrubs/rhododendron/pruning-rhododendrons.htm