There is not a real simple answer to your question :-) Yes, they did not bloom as you expected because of the pruning. Most types of mophead hydrangeas (H. macrophylla) bloom on growth that was produced the previous season. If you prune in spring or even too much later than the actual bloom time, you run the risk of removing any potential flower buds. Often you will read to prune immediately after the bloom cycle but hydrangeas in my climate bloom well into fall so in my area it is generally recommended not to prune, as any flowering growth for the next season has already been formed. Your climate may prove different, but if hydrangeas are in bloom in your area now, I would avoid any pruning. Period. There are reblooming mopheads available - those that bloom on both old and new growth. Pruning is not so critical with those as even if one removes the flower buds on the previous season's growth, there is still the potential for a later bloom season on the current season's growth. Other than deadheading or a very infrequent pruning to reduce size, there is no reason why one would have to prune a macrophylla on any sort of routine basis except to remove any dead wood.

Starlight I grow 3 hydrangeas at varying distances from the maple: 1 arborescens (6 feet), 2 macrophylla,Twist n' shout 9 feet, Endless summer 13 feet. The tree is in my neighbour's front yard and is seperated by their pathway from our yard, which is slightly higher 2-4 inches. The maple's canopy starts way up. But the roots are all over the place, and unless we have major showers no rain can past that canopy. H. arborescens is really big and continues to sucker all over the place. It is rarely watered in the summer. but it thrives. However, both macrophyllas are water hogs. Mulched, mulch-less they drooped especially the 1st 3 years. Remember my soil is 100% sand. In the first 3 years, I had to water it regularly. Sometimes every day (especially in heat waves) or every 2nd day. I just put the hose in it's crown and let them drink. However, since this year, 5th year, I have to water it much less. Maybe once a week if we don't have any showers. The plants are healthy and flower. Mine receive dappled light and some 1 or 2 morning sun. And the one that receives the afternoon sun hates it. In retrospect, if I had amended my sandy soil properly with organic matter, I might have a had a better result. SG the worse year with the hydrangea was a freaky one when the snow melted in mid March and then we had a freakish cold weather -4 wind chills etc. That killed all the top buds. Last year, during the polar vortex I couldn't cover the top buds of Twish and shout. Nothing happened to it. From my experience it isn't the winter but a roller coaster spring that can kill the confused buds on the old growth.

Being a mophead, I would expect that it would turn blue-ish in acidic soil but, oddly, Wayside says nothing about blues or color in acidic soils. Maybe they just left that out? I have looked at pictures in their website and on the Internet and all I saw was pink. Could it be like some of the pink Annabelles that stay a shade of pink in acidic soil? Hmmm. Wayside info (from their website): "From fine Japanese breeding comes this exceptional Hydrangea, its petals forming a slender star on every floret! With changing colors and increasing bloom size over time, 'Inspire' is a terrific addition to any shade landscape. The first petals are chartreuse, deepening to pink and then to purple over time. New petals arise as the flower matures as well, increasing the size and density of these big mophead blooms. So showy, so long lasting! 'Inspire' is just 3 to 4 feet high and wide, with a dense habit and plenty of blooms arising on old and new wood. This is a great shrub for northern climates, where late spring frosts may kill the first set of buds but not prevent subsequent flowering in summer and fall. But it's also quite heat- and humidity-tolerant, making it a good choice for the south, mid-west, and far west as well. Site 'Inspire' in partial shade everywhere but the northernmost edge of its hardiness range. Like all Hydrangeas, it appreciates regular moisture, but beyond this has few requirements for success. Prepare for many seasons of ever-changing beauty from this remarkable shrub! Zones 5 to 9."

don't prune it!..I had a macrophylla in a pot..I overwintered it in my shed several winters in a garbage bag filled with leaves..it always bloomed..I basically never pruned it..only dead or damaged flowers/stems.. couldn't find the pic when the blooms were pink..I got tired of the routine and planted it outside in an out of the way spot..if it doesn't bloom so what..this year my macs bloomed.. better than zero blooms but unattractive compared to some of the paniculatas I've seen.. do you have sun?..plant paniculatas..arborescens bloom for me and I like them..but I see paniculatas here that are to die for.. I just bought 3 oakleaf hydrangeas..I think they'll do better in my shade than a paniculata.. arborescens hydrangeas..