I protect my hydrangea serrata ‘Artic Blue’ for the colder months. The first winter, a large plastic pot could cover the entire shrub. After the second growing season, it became too large.
Then came the shrub protector. It collapsed after one storm. Some of the branches broke, others poked holes in the cover.
Tried leaving the shrub uncovered the next winter. Lots of winter kill and no blooms.
Last fall, I planted a few stakes at the drip line and wrapped a black mesh pool cover all around. This left the top uncovered but protected the shrub from icy winds. After the second snow storm, the stems were well insulated. This summer, the shrub was covered with blooms.
The stakes went back a few weeks before the ground froze. When the weather turned cold, the wrap was put in place. After the first storm, I packed snow between the stems.
I decided to try the same protection for a hydrangea macrophylla that hasn’t bloomed in a long time.
Now I wait for spring and hope for the best.