Hydrangeas: Saving a florist hydrangea, 1 by DonnaMack

DonnaMack wrote:
I am in zone 5a and have overwintered two young hydrangeas in my unheated garage through brutal winters, and in my garage the temperatures are much lower than yours. I start withholding water, which makes them go dormant, such that I give my two hydrandea pots about 8 ounces at the beginning of each month. I see that you do not have an answer yet so I thought I'd respond.

I would recommend cutting the lovely flowers off (as I do) and then reduce watering by two thirds. When you want to rejuvenate them for the next season start watering them again, and when they break dormancy move them outside, give them some compost and triplesuperphosphate and epsom salts. Give them some more time before you give them fertilizer.

You will amused to know Endless Summer is really an old florist hydrangea that was recognized for its ability to flower on new wood and patented. It's not new at all, and started like yours.

Here is a picture of a hydrangea Shishiva (more tender than your plant) that started out the size of yours and has spent 3 winters in my garage.

I hope that someone in your zone will chime in.

Donna