Your endless summer will bloom on new wood so yes, it should flower this year. Hydrangeas will flower best when they are fed. Nothing will boost more flowers than feeding it Jack’s Classic Blossom Booster every week and a half from now through mid August. Dilute as directed on the package and pour the food on the soil below the plant keeping the leaves as dry as possible. HERE’S A LINK to more on care of you Endless Summer hydrangea.