They will grow in sun or shade when you plant give the plant a good drink and it should do well we the flowers die remove and a second show should come along don't know what color it is but rusty water will change the color.

Oh my there are so many hydrangeas now. There is actually a hydrangea forum, so they should know. I grow Lady in Red in the shade, Limelight in the sun, and Oakleaf hydrangea in shade. I think the Endless Summer ones are good but there seems to be a new variety each day.

Definitely go with an Endless Summer cultivar, they seem to do a little better with our heat. I transplanted mine to the north side of my house juuuuuust at the edge of where the sun peeks over the building, and they LOVE it. I advise the same. I also transplanted a little one that someone had planted under a bush (what the...??) beneath my oak tree's outer reaches, so it gets dappled shade. It has taken off like crazy, loves that location. That one is a Glowing Ember or something like that, stays smaller.

For your described situation, I might suggest putting one either at the sun/shade line on the north side or beneath the shade on the south side. See what that gets you, and don't spend more than $20 on each plant, in case they don't work out.

bon chance!