I would wait until it's almost ready to bloom before removing any canes that look "dead". You may get some sprouts on a couple lower sets of nodes on those older canes and retaining at least those can help to build up a taller shrub.

You may not really need to overtly fertilize your hydrangea outside of putting some compost around it and mulch to help retain moisture. Hollytone is a good "natural" fertilizer, but note that it has an acidifer in it, which would make ES more blue (assuming there's some natural aluminum in the soil) if that is what you want.

Thanks jenny. I already killed one ES trying to get it to turn blue...it turned black:>(
This gardening 'hobby' is getting very expensive!

How did you kill it trying to turn it blue? I ask because I just purchased some and would like for them to be blue, but the amount of acidic fertilizer that the lady at Lowe's recommended seemed like way too much.

While some people choose not to fertilize at all, most nurseries that I have purchased from, describe them as hungry feeders that do best with frequent fertilizing. A lot depends on the quality of your soil I'm sure, but I couldn't live without it down here in my sandbox of a garden.

Aluminum sulfate is often used to color hydrangeas blue. It is NOT a fertilizer and if applied too heavily, it can damage or kill a hydrangea...yg