Hmm, I assume they are not in dense shade or planted too deep? If they appear "identical" above the ground, I would start looking underneath. Are they getting the same amount of water? How are the levels of nitrogen, potassium and phosphorus (check with one of those cheapo kits or do a soil test). Even though they are close to each other, check the soil pH too anyways. You do not want to see high nitrogen levels as that produces lush dark green leaves. And no blooms.

Some F&E hydrangeas are only hardy to Zone 5 so I am not sure if hardiness is an issue where you live. Blue Haven, Peppermint and Together (note: those are the only ones that I know) are only hardy to Z5. Those would need winter protection in Zone 4 or less.

Last possibility, SOOOOOMEONE has been chomping on your hydrangeas' flower buds. Very likely Bamby and you would need to either protect plants somehow or spray them with something that will keep deer away.

The part of all this that bothers me is that F&E should bloom in Spring and again in Julyish and yet again in some areas. So I wonder if you can monitor the plants this year and see if you notice when the invisible flower buds open (they look like broccoli growing off the stems' ends) or if they do not.

This post was edited by luis_pr on Thu, Jan 22, 15 at 20:44

With last winter's frigid midwestern winter, it is also possible that the one that didn't bloom was more exposed than the others and so had more bud kill. There are other possible stressors such as root competition from nearby trees or voles eating roots that may have prevented this plant from blooming.

It is also possible that they aren't all the same variety, either due to mislabeling or just different varieties from the F&E line, and the one not blooming isn't bud hardy where you are. One thing to try would be to give it a winter blanket to help shelter it. Do a web search for winterizing hydrangeas to find out how. This would at least help answer whether it's a variety problem or a culture problem.

Such variation in individual performance is often seen in shrub plantings in general, including hydrangeas. In fact, I would say it is somewhat unusual to see a grouping of one kind of shrub with each individual displaying the same amount of flowers as the others. Maybe next year your results will be different than they have been.

I had the same problem with a Mini Penny hydrangea. It was beautiful the year I bought it, but after that it was just a green bush, with one or two blooms a year. I moved it too an area with more sun, fed it, didn't feed it, nothing helped. I don't have to worry about it this year because I moved and have to start from scratch.

Maybe you needed to insert a penny into somewhere, like with a gum machine.