Is the hydrangea being watered regularly (or monitored for watering needs) now that our weather pattern has entered near-drought conditions recently? This leaf damage is not caused by a pest or disease, and looks like scorch, which is environmental damage from high temperatures or dry roots. The foliage isn't wilting in the photo, but scorch can occur before that happens.

The lack of flowering could be due to several reasons. Do you know the name of the cultivar you're growing? If so, we can tell if that is winter-hardy enough to have the flower buds survive our winters. Not all hydrangea cultivars are equally cold-hardy, and those in particular that are sold forced into early bloom as container plants for indoor décor (like around the spring holidays such as Easter) tend to be too cold-sensitive to have flower buds overwinter here.

Other reasons for lack of bloom in this kind of hydrangea is pruning at the wrong time of year, having the buds eaten by deer (though it's less likely they'd eat them all), and having a late spring freeze kill buds that already broke dormancy from an earlier warm spell. The latter is an issue of growing concern as our winters warm. Often, we find that missing blooms are due mainly to pruning mistakes. Was the plant trimmed at all between midsummer and spring? If so, flower buds that formed the prior year that would be opening the next summer will be lost, and not all hydrangea varieties can replace them in time to flower that same season. "Reblooming" types can, but not all of those sold these days can do this, as it's a fairly new trait in hydrangea breeding.

If you can, try not pruning the plant at all between about July and next May/June, to allow any flower buds it does grow time to mature, stay dormant this coming winter, and then open next year. If this is a variety we suspect is not hardy enough, then there is little that can be done other than to try moving the plant to a more sheltered location out of the winter winds, or perhaps blanketing it overnight during cold snaps. Otherwise, you could replace the plant entirely with a cultivar that does rebloom, which will allow it to more easily replace lost flower buds, even though that would delay bloom by several weeks. (That said, it's still best to not prune them back over the winter, which many gardeners do without realizing they are cutting off buds.)

Miri

Thanks very much for your advice. I will follow your instructions about pruning. I will water longer with each watering to combat the heat problem. 

You're welcome!