Let me clarify one thing. The hydrangea was root hardy which meant it survived the winter and she always had foliage, but as hydrangeas produce flowers on old wood, if she didn't find some way to keep those stems and branches from dying during the cold winter months, she would never get flowers.
So, this is what I told her to do to protect those stems and those potential flowers.
1. Do this after the plant has gone dormant--Depending where you live this could be late September to mid October. It's safe to say it's some time in the autumn after foliage has dried up and fallen off.
2. Using chicken wire at least a foot taller than the plant's tallest stems, fence in the plant. Anchor this with stakes to keep it from falling down.
2. Leave enough room around the branches for a few inches of space.
3. Take dried leaves--oak leaves would be great for hydrangeas because of their highly acidic nature which Hydrangeas love, but any kind will do--and stuff them loosely around the branches making sure there are no huge air pockets.
4. As winter progresses, these leaves will pack down, so have a ready supply of dried leaves to refill and keep the branches covered.
5. In spring after all danger of frost or when growth starts to show on the stems, remove the leaves and toss into the compost pile.
6. Cross your fingers and hope for a miracle. If it blooms, it worked, If not...well, at least you tried, right?
I told my Uncle Julio to try this method on his fig tree which, after particularly rough winters, didn't quite make it through the winter. The roots did, just not the branches and so, he wouldn't get the plant big enough for fruit production. Whether he tries this, is up to him. His tree would need a fence at least 6feet high and several feet in diameter, plus an entire maple tree's worth of leaves for insulation. Yes, some would say this is going to extremes for blossoms and fruit, but what the hey? If you're willing to try, you may get nice results from relatively little effort. Worth a shot, I declare!
* My apologies to Raymond Alexander Kukkee who begged to know this method of mine in time to save some of his plants. I never said I was as timely as Incoming Bytes. Sorry!