It depends I guess. If you care for fragrance phlox would be the way to go. I hate the washed out brownish look of hydrangea blooms once they are past their prime and the bare branches throughout winter aren't pretty either. But a lot of color options and bigger blooms make hydrangeas attractive. I think both have long bloom season.

in my experience.. hydrangea tend toward early summer bloom.. and phlox toward middle late ... but some of that might be that as kids we always bought one for mom for mothers day and or easter .. and of course they were probably forced into bloom .. so maybe my bloom time recollections are off ..

but.. and this is important ... there are all different kinds of each plant.. and you will probably need to get to the latin name level .. to be clear about your specific options ...

best suggestions might come for a pic of the corner from last year ... if you happened to have one ..

ken

How do you feel about conifers? A conifer can give you all year interest vs just spring or summer. Is this a corner by the house or in the garden? I would not suggest if by the house, but if in the garden...the sky is the limit!