Did you prune your hydrangeas? Many hydrangeas will not flower if you prune back the branches as they bloom on two year old wood. Are they getting enough sun? Many shrubs including hydrangeas need at least a half day of sun to flower. What about water? Plants that are thirsty will not waste energy making flower buds. Finally, is your soil fertile enough? It won't hurt to add a slow release all purpose plant food like Osmocote around the base of your hydrangeas in spring and this may kick start some flower action. Keep growing, Marianne Binetti