Getting Your Hydrangeas Ready for Winter
If your hydrangeas live in a cold climate, late fall weather is the perfect time for them to harden off, you can use this same time to prepare them to make it through the coming winter.
Exactly what you do depends on what kind of hydrangea you have and where it lives. But the good news is the only ones you really have to worry about are your hydrangeas that flower on old wood. Their flowers have been forming on the plants since August and those are the buds that you need to protect.
For the most part, climbing and oakleaf hydrangea flower buds are more winter hardy than those of bigleaf hydrangeas. In my zone 5 gardens, when my bigleaf hydrangeas have suffered winterkill, my oakleaf and climbing hydrangeas have flowered profusely with no protection.
What this all comes down to is the one kind of hydrangea that needs your intervention: bigleaf hydrangea (macrophylla). I call it the troublemaker.
Make an A-Frame for Hydrangea Protection
Snow can be a protective blanket in some cases or it can break and distort the stems when it is heavy and wet. In view of that, one thing to consider is an A-frame to shunt off the snow. It still allows the snow to build up at the base of the plant which can be a good insulator. You can build an A-Frame from a discarded pallet as shown in the photo or buy one. There are lots of DIY plans online.
You can protect your plant by erecting some kind of temporary windbreak. Hydrangea macrophylla buds are killed by icy winter winds which desiccate tender flower buds.