Certified GKH Gardening Expert
Here is how I like to treat cut Hydrangea!
When I cut them outdoors I put them in a bucket of fresh water.
After bringing indoors I recut the stems and place them in hot water for at least 15 mins.
Then I place them in fresh room temperature water and add floral preservative as directed on the package.
Every couple of days refresh the water and recut the stems if the flowers are wilting.