Wow, your hydrangea does look happy with new growth. Did you fertilize? Hydrangeas grow best with a slow-release plant food once in the spring. I just spread Osmocote Plus around the roots when I see new leaf growth in April and then no more plant food. You can prune off the blooming flowers now as it looks like you have a traditional Hydrangea macrophylla that flowers on two-year-old wood. This means the few branches that bore blooms this summer will not flower next year. You'll be able to cut them now. For maximum blooms do not prune the new growth now or in the spring. The less pruning the more blooming. Give this shrub plenty of room and it will be a beauty. Keep growing, Marianne Binetti