It will bloom don't worry! You will probably not see buds until July. You should prune between late fall to early spring. I wait to early spring so I can enjoy the dried blooms through winter. You can prune it as hard as you want or as little as you want. I have noticed the harder I prune the larger the blooms I receive.

I'm just starting to get flower buds on quickfire which blooms much sooner than pink diamond...patience.

Too early for PD blooms in Zone 4, I agree. Only Macs blooming over here and just barely. The Lacecaps are the ones which usually start the show here. Those have started blooming but the mopheads... those are in the broccoli stage or barely starting to bloom. Not surprising that you do not see any blooms yet.

When did you prune it last year?

'Pink Diamond' is a paniculata and blooms on new growth. When it was pruned should have very little bearing on how well it blooms or doesn't. Even a mid spring pruning on these plants should still result in flowering - you just want to avoid pruning after the buds have set, which in my climate is late spring/early summer.

Paniculatas are the most sun tolerant of all the hydrangea species and planting in excessive shade could impact the ability to flower well. IMO, this is a full sun shrub.

I know this is old but my PD is blooming like. Lace cap, flowers only around the outside tons of buds but they're not opening and have turned from white to pink while still in bud form. Any idea why? It's in the sun from roughly 1130 -sunset

Pink Diamond IME has a mix of sterile (large) flowers and fertile (small bud-like) flowers. I don't know if the balance between the two is variable year to year or under different conditions. The polinators like the fertile flowers, and I like the looser look this gives the flowerheads, but you may not. Pinky Winky, Limelight, and Vanilla Strawberry have many more of the sterile flowers so their flowerheads are densely packed and heavier looking.

See link below for photos of Pink Diamond flowers. Do a similar web search for photos of the H. paniculatas listed above to see how they differ in flower density, color, and flowerhead shape.

Here is a link that might be useful: Pink Diamond flowers

I have grandiflora and limelight and invincibelle , I guess I just figured since it was a paniculata that it would look more like my Grandiflora. So is this pretty much normal looking to you ? I don't find it unattractive just want to make sure it's healthy. Thanks nhbabs.

It looks healthy based on what I can see of the plant, but it does look a bit sparser than some I've seen. I wouldn't worry about it since it looks healthy overall and it is always less full than Limelight or PeeGee IME. It will be interesting to see if it is a bit fuller in future years; I don't grow this one, so I don't know how variable it is as conditions vary.

Okay thanks, I'll hope for more next year. I just took the photo of the flowers since that was where my main question was.... I hope I come to like them, since I have two. I guess my exp with paniculatas does not apply to these, but the leaves and form of it are nice so we shall see.