hydrangea helpand canna not flowering

Ihave a hydrangea in a pot of new compost which hasnt flowered this year .Help please.also the Cannas have had lovely leaves but no flowers for the second year.Hope you can help thanks.:
Calla 1.

 

Carolla, preferably, can you let us have some pics? If not, then it`s going to be guesswork. With the Hydrangea I would say that it is in the wrong compost, probably multi purpose, when it should be ericaceous. The Canna, I couldn`t really say without seeing a photo.

 

Did you prune the hydrangea this spring? Did you have late frosts? Either of these can have killed the blooming buds. Leave it alone, unpruned, nad see that it is not in too exposed a site, especially in spring, when the buds break. A snug hat of orticultural fleece in a late cold spell can make all the difference. Acidic compost won't go amiss either, as Dave said