Speaking of rooted cuttings...last year I bought 2 Pinky Winkies that were basically rooted cuttings. They were small sticks w/a few roots. I bought them from Lowes bc they were only 15$ each. This year they are already up to my chest-full beautiful shrubs. I planted them last June! The problem is my Pinky Winkies are actually Quickfires! They look great though. I bought 2 other PWies that I think are turning out to be Little Lambs (they have pink stems but are staying shorter and the bloom last year looked more like LL). And 1 of my larger Quickfires I bought from a good nursery doesn't have any buds yet despite all my other QFers budding up already so I'm waiting to see what that one actually is. Mislabeled plants are so annoying yet seems to happen often!

NHBabs, northwest of Chicago. Like Luis, I add compost and fertilizer, but some hydrangeas even if deemed zone 5, just refuse to make it more than one season (Abracadabra Star was one). I bought All Summer Beauty online because it's impossible to find at a nursery here and my friend swears by the abundant blooms of it. My first time ordering and they are LITTLE!! Hoping these can be companions to my endless summer or I'm going to have to go with a small paniculata or oak leaf.

My Tuff Stuff has survived -23F without showing any issues and blooms well on new wood. I don't know how much colder you expect to get than that. Although I only planted my Tiny Tuff Stuff last year, I haven't been impressed so far. It is so small that I thought it had died and although I recently discovered that it didn't it is so tiny it has no current value in the garden. Perhaps in a small courtyard or if I had an apartment balcony it would work well, but in my garden it's so small that it is getting overwhelmed by even relatively small perennials. This isn't an issue I've had with other hydrangeas.

I'd honestly choose another plant and put the Hydrangea somewhere with afternoon shade. Shade cloth isn't ornamental, and full western sun in TN will make the plant(s) leaves look damaged. You could try one of the smaller Hydrangea paniculata types such as Bobo. They are white-flowered, turning pink late summer, but are long blooming and far more sun tolerant. I can grow them where they get more than 12 hours of sun here, but I haven't ever gardened as far south as TN. Or choose another type of shrub entirely that is more tolerant of hot sun.