I have 6 hydrangea plants growing in partial shade. How can I get them to flower?
Baltimore County Maryland
Some reasons for few or no bloom include improper pruning, cold damage which kills flower buds but often not leaf buds so you have a living plant with lush foliage but no flowers, (site may be more susceptible to cold), and too much nitrogen fertilizer.
You dd not mention the type of hydrangeas you have. If you have Hydrangea macrophylla, bigleaf hydrangea, the most common type, this can be susceptible to cold damage. We did have some late spring cold snaps this year.