'Pink Diamond' is a paniculata. It is very cold hardy (z3), blooms on new wood and is happy in as much sun as you care to give it. All in all, a freely blooming hardy hydrangea that can take some tougher conditions.

If planting in clay soil, dig a wide, shallow planting hole, site the rootball so that it is slightly above grade and backfill with the soil removed (no amendments), creating a small mound. Any amendments you care to use should be applied as a mulch or topdressing around the planted rootball. Water in well and as often as necessary to keep the area moist (not wet).