For a "hardy" hydrangea in z5, I'd look to a paniculata. While these start out white, the flowers on several cultivars will take on pink tones pretty early in the process - 'Pink Diamond', 'Pinky Winky', 'Vanilla Strawberry', 'Strawberry Sundae' and 'Quick Fire' (the names provide a clue to the coloring :-)) would be ones to consider.

There are some reliably pink macrophyllas - like 'Glowing Embers' or 'Pia' (aka Pink Elf) - but these would need winter protection in your zone to produce flowers so I hesitate to call them 'hardy'. There are other macs that will produce pink flowers in less acidic, more neutral to alkaline soils but few that are really color stable like the two listed.

And I believe there are some newer introductions with smooth hydrangeas, H. arborescens, that produce pink and even lavender flowers but this is not a species I favor so I'll leave comments on these to others. They are very hardy shrubs though.

Any particular size shrub you are looking for?

In general in my cold temperatures and acidic soils, H. macrophyllas are less reliably hardy as well as rarely pink rather than blue to purple. I do have a related H. serrata 'Tuff Stuff' that blooms purple and ages to pink in my garden. The blooms are lace caps, and it is blooming by shortly after July 4th, and this year I am noticing 'Tuff Stuff Red' which you might want to check out if you like deep pinks. No personal experience with it, but I have been considering trying to find a spot for it since I really like 'Tuff Stuff'.

I am not fond of the shades of pink and mauve Hydrangea arborescens I've seen, though I like the white ones. Perhaps others have found ones they can recommend, but they look rather muddy to my eye.

Which means I will like GG48 be recommending H. paniuclata which for me have been both easy and reliable. The panicles of different cultivars vary a fair amount with regard to shape (pointed vs rounded and overall length); flower density; and timing of the flowers' emergence and color shift to pink. Some stay more tan-pink, while others develop quite a rich deep pink. My personal favorite is Quickfire, which grows about 6' tall and is my earliest to bloom, starting by July 4 or earlier and then starting to shift to pink about a month later. By early September it is a rich pink which it holds on to until hard frost, so I get 4 months of bloom, 3 of which are some shade of pink. I like the mid-sized, rounded, lacy panicles.

Some of the really large ones seem overblown to me, though other folks seem to like them. With the lacier panicles, I don't need to worry about them flopping in heavy rainstorms. However, since what is appealing tends to be quite personal, I would suggest that you look at lots of photos of different cultivars of H. paniculata and then check back here to see if folks can weigh in on ones that you like as far as how early the bloom starts and how quickly they move from white to pink.

Thank you everyone for the info. I do have H. paniculata, but I'm looking for something smaller. Babs, that's a beautiful pic.

Bella Rosa, how small is smaller? Look at H. paniculata Bobo and one that Rouge 21 recently linked to in a thread on this forum, Lavalamp Flare. Both should stay under 4'. Then there are a whole passel of them that are 4'-6'.

IME experience most H. arborescens are in the range of 4' or a bit more, so you could go look at the pink ones in nurseries to see what you think of the color.

My original Tuff Stuff dies back to the ground most winters, but grows quickly to about 2 1/2' and blooms starting in July, so there is hope that the newer Tuff Stuff Red (though it's actually dark pink) might do the same.

NHBabs..just wondering where your Tuff Stuff is planted?..eastern exposure?..near a building?..have heard this one is more reliable than other macrophyllas..

NHBabs..I love it..sounds like a decent microclimate where it's planted..is it your only one?..would it perform as well if in a less sheltered spot?..trying whatever I can to grow a big leaf that blooms..

It's my only one. I tend to buy one of several plants to see which does best. This one has turned out to exceed my rather low expectations and I like it better than any of the macrophyllas I've tried except perhaps Twist and Shout.

Bella Rosa, are you somewhere with acid soil or is your soil closer to neutral/alkaline? All of the macrophyllas and serratas I've tried have been blue just due to soil pH (acid). I am of the philosophy that life is too short to try to change my soil pH since it would have to be a constant ongoing chore.

NHBabs..my 2 Twist and Shouts have also bloomed (my only Macs that bloom)..when May's here I'll look for a Tuff Stuff..wish I would've started with just ONE Endless Summer..live and learn..