The Nikko Blue hydrangea and its variants are classic plants in Yankeeland. Mine are in their full glory today.
Hydrangeas are the sorts of things that make a house a home.
Here are three important tips for those who grow hydrangeas of any type: first, they like moist (but well-drained) soil, hence their name. Second, full-day direct sun is too much for most of them unless you have irrigation. Third, prune them with caution: you have to first determine whether they are macrophylla or paniculata, etc. Prune them wrong and you get no bloom. Better yet, don't prune them at all unless you have to.
(More general shrub pruning info: Except for hedging or shaped shrubs, mature shrubs can or should be pruned at ground level - not from the top - removing 25-30% of the woodiest growth to keep the plant young and vigorous. This is especially important with shrubs like Lilacs. I will try to dig out my old pruning posts. Always study the correct pruning technique for a given plant before attacking anything with a sharp tool. Never prune young shrubs.)