I purchased some strawberry and cream hydrangea. The tips of the leaves are turning brown, then work its way down the leaf. It looks like a blight, but not sure. I don't see any insects on the leaves eating them, but my eyesight leaves a little to be desired.
Typically, in hydrangea, this is caused by a watering issue. If they are newly planted, there may be gaps in the soil around the root balls that are drying out the roots. I would tamp down the soil around them well. I would also recommend upping the watering for the plants.