Why is it when I put cut hydrangea blooms in water they wilt and appear to die?

Question:after a few hours??

Answers:
This is caused by a sticky substance that clogs the stems, preventing moisture from reaching the blooms. This does not happen every time. Cut-hydrangeas often last for days and other times they wilt almost immediately after being added to an arrangement.

There are two techniques that should solve this problem. I've tested both, and have had excellent results. The two methods are:

(A) The Hot Water method
1. When cutting hydrangeas, take water to the garden in a container.
2. Immediately after cutting each bloom, drop the stem in the water.
3. Indoors, boil water and pour it into a cup or any container.
4. Cut the hydrangea stems to the desired length.
5. Stand the stems of the hydrangeas in the hot water for 30 seconds.
6. Immediately put into room temperature water and then arrange

(B) The Alum Dip method
1. The alum used in this method can usually be found in the spice section of the grocery store. Occasionally it is found with the pickling supplies.
2. Plan to cut hydrangea blooms in the morning while the weather is cool.
3. Take a pitcher of water to the garden and drop bloom stems into water immediately after cutting them (important).
4. As you arrangement the blooms, recut the stems and dip the bottom 1/2 inch of stem into powdered alum.
5. Arrange as usual in water. (I know this washes off the alum, but it works!)

Hope this helps! Good Luck!