Cut the stem at an angle while it's under water. Wrap a wet napkin or a little newspaper and rubber band a ziplock bag around the stem after you cut it. Then you can flip it upside down and soak the head in room temperature clean tap water in your sink. Soak the flower head for at least an hour. Let the excess water drain off and trim the stem again before adding it to your arrangement. The longer you soak the heads the better. Remember fresh flowers do better in cool areas if you have room you can put arrangements in the fridge at bedtime and remove them again the next morning....if your fridge is set to recommended temperatures. Always keep your container clean and full of fresh water.
Soak them in water and they perk back up!
Dip the cut end in Alum powder before you put it in water.
It helps flowers with woody stems absorb water.
I soak mine in the kitchen sink completely immersed overnight.
Thank you all
sometimes when you cut hydrangeas they form a sticky substance over the cut that prevents the flower from sucking water up through the stem.To prevent that “sticky stuff” from forming you need the secret ingredient- alum! (A common ingredient used for pickling, find it in the spice aisle.) When you are arranging your hydrangeas re-cut the stem about an inch above the previous cut and immediately stick the bottom 1/2″ of the stem in the alum to coat it, then arrange as usual. It’s easy and works! No more wilted hydrangea blooms!