If your hydrangea blooms wilt soon after you cut them, take a bucket of cool water along the next time you go into your garden. Drop the stems into the water right after you cut them. Back in the house, boil some water and let it cool for about a minute. Re-cut the hydrangea stems to the length you want, and pop them into the hot water for 30 seconds. Now put the stems in room temperature water and arrange as desired.