Both are H. paniculata's, 'Angel Blush' being a recent Monrovia Nurseries introduction with white flowers that turn to pink and then to red, they say.
Paniculata's require full sum to partial shade and reach a mature height 8-10+ ft. They bloom on new wood in late summer and can therefore be pruned/shaped after blooming until the following spring. Once established, they require little care, except for removing spent flowers and some dead wood each year. They can be trained into a single standard(tree-form) by severe pruning of canes while they are young. I grow both, the single and multiple stem types, and I really prefer the latter. Fall planting is best, but be sure they receive adequate moisture until they are well established. At first sign of leaf wilt, be sure to water them, as they can defoliate almost overnight, it seems. If that occurs, they will usually recover after watering and grow new foliage, but you will be staring at bare limbs for several weeks.(My experience). Once established, they are fairly drought tolerant.
Rb

Rb,
Thank you for all the information. One more question - what about "Limelight". Are they similar to Tardiva and Ruby, as far as requirements? Also, is now a good time to plant, or should I wait until late Sept (cooler temps)?

Limelight would be the same as the other two as far as cultural requirements. Now is a good time to plant, in your zone, but keep them well watered. I haven't grown Angel's Blush, it sounds lovely, but Tardiva is almost too late for us here in Zone 5, by the time it gets its flowers it's almost frost here. Pretty though. So expect the flowers on Tardiva to be late. I love Limelight, In my personal opinion, I think it is the best plant any garden can have (just my opinion).

'Tardiva' is one of the most upright (if not the most) in paniculata family and as Polly correctly pointed out, it's THE latest of all to bloom. Even here, in 6b and full sun, it start blooming toward the end of August, while other cultivars already in full bloom in a middle of the month. Therefore, you might have a very short season to enjoy it in your zone.
If it will be me, I wouldn't waste prime garden's real estate (and Tardiva takes a lot of it) on it.
It is doesn't matter if price is right or might be even a bargain. If plant is not right for zone or location it's just a waste of money, space and time, IMO.
If you like a 'Tardiva' flowers look, try to find a 'Kuyshu', the same size, the same upright form, similarly looking sterile+ fertile florets and THE first to bloom even in part shade.
You may end up paying a bid more as it's not as widely available as 'Tardiva', but you definitely will have more bang for your bucks.

I'm kinda of suprised to read that Tardiva blooms so late. I saw them blooming at the Chicago Botanical Garden and they looked so beautiful! Well, I'll plant it on the side of my house, water it well and hope for the best! Thanks everyone for all of the info.

Angel's Blush is beyond gorgeous and is definitely on my list of plants to get next year! The flowerheads are so big they look like a dessert....

Putzer,
You're right. The blooms are stunning and HUGE! I can't wait to plant mine in the next couple of weeks. I'm waiting for cooler temps. I might have to go back and get a few more!

My Tardiva has been in it's shrub border spot for about 4 years and has lovely 6 foot stems with healthy green leaves However...it has not bloomed since the second year. I cut it back to 6 inches early every spring. What is the problem? Anybody else experience this?

Why do you cut them to 6" every spring??????

too much pruning....

Hmm,. I'm listening closely to this discussion having just planted my Angel's Blush, Pinkdiamond and Kyushu. I have a three year old Tardiva and I never prune it. I don't think they really need to be pruned much. The Tardiva is great - compact, upright and right now turning pink from the white blooms. My "little ones" are just about 6 ". I think they'll make it.

You can certainly prune panicuta, but they are not normally pruned to the ground in the spring. That may not be the issue, but I would try not pruning them and see if they bloom. I prune mine to shape and deadhead in the spring just as they are breaking dormancy.

I know I'm a little late chiming in on this discussion, but hope someone has some answers. I was considering purchasing some Tardivas next year. I saw some near Minneapolis in early August and they were covered with blooms. When you say they bloom really late, do you mean it takes a long time to get the pink color on them? Could they have just been blooming early this year due to the heat here this summer? Any thoughts, knowledge, opinions would be appreciated.

" I saw some near Minneapolis in early August and they were covered with blooms. "

Did you see them blooming being planted in a ground or in a pots at the nursery?
If later, that's right, they've been forced into early bloom for the marketing purpose.
Mine planted in full sun and are the latest of all paniculatas to start blooming (mid to late August).
In my zone this is no problem since they have plenty of time to go thru all color changes, but in z4 you'll have much shorter period between white and brown stages.

My Tardiva blooms Mid August. From what I've read it is the latest panicula to bloom. The blooms start turning pinkish about mid September.

I have pictures of mine in full bloom on August 23 of this year. I think it had already been in bloom for a week or two at that time. Blooms started turning pink sometime in September. I wouldn't worry too much about frost shortening the bloom times - although Minneapolis is colder than I am in Madison. Mine still have good flowers although we are expected to reach freezing temperatures for the first time this week. A couple of frost warnings prior to this but no damage to plants yet. Brrrrrrrrr!

These were in the ground,were about 8 ft. ft tall.

What diameter can I expect my Hydrangea Angel's Blush shrub to take up? I'm in zone 3 and have been assured that it will do just fine in Calgary Alberta.

I read this thread too & a few others ... convinced, I started hunting (in town) for one since & finally found, a real baby size, this season, for a site that can take an full grown, 10'ht x 8'spread bush. The little 1gal baby has grown more than twice its size since planted in mid-May & flashed promptly being 1st season in the ground. If you have room in f/s I think you won't be sorry! QF in your zone, will bloom sooner, if it makes a difference

Good luck & have fun!