Browning near the edges that moves inwards suggests insufficient soil moisture. Overfertilzing can burn the roots and cause similar symptoms.

Here is a picture of fertilizer burn leaf damage:
http://www.ppdl.purdue.edu/PPDL/weeklypics/8-23-10.html

CH is a vigorous grower so a lot of fertilizer is usually not needed. Just mulch it well, keept the soil as constantly as you can and give it time.

To put things into perspective, for a newly planted hydrangea, one or two applications a year of 1/2 cup to 1 cup of compost, composted manure or cottonseed meal should be enough. Or one or two applications of a general-purpose slow-release chemical fertilizer per label directions.

Some versions of MiracleGro have up to 30% nitrogen so be careful since too much nitrogen can inhibit flower production.

Here is a link that might be useful: Fertilzing hydrangeas

Thank you much. I'll start watering the heck out of it.

My climbing hydrangea has the same problem. I assumed it was just from too much heat since I do water quite often.

I have had this plant for at least 7 years and it has never blossomed. IT also grows VERY slow.

It was the H~E~A~T~W~A~V~E that burned much of mine under noon sun ~ much more than yours, Vision6800. Mine is 6y/o & is finally *Taking off w/o looking back* as expected after a few years in the ground. They do recover but will just have to suffer the burned look a while.

We're finally getting a respite from the heat here & got a good down pour & dousing all of yesterday ~ I hope you get the same gift from Ma Nature!!!