Keeping Lilacs Fresh

What is the secret to cutting lilacs from the yard and having them keep nice. It seems they wilt in just a few hours.

Suggestion from florist in New York:

The key to picking flowers from the garden is to do it early in the morning. And, with the lilacs, pick them with at least a third of the flower head still in bud. I use a sharp pair of pruning shears and immediately put the stems in a bucket of warm water with floral preservative.

I grow perennials and often use flowers from the propagation beds. I also cut them and put them directly in a bucket with floral preservative, but since I cut EVERYTHING under water, I again cut them when I bring them in. I've been doing this for years, ever since I read about Japanese designers cutting every stem under water before placing them in the arrangement. I'm not THAT fanatical, though I faithfully do it when processing the flowers.

A few years ago a rep from Floralife did an educational thing at my wholesaler, part of which was proving what a difference it made to cut flowers under water. He took two bunches of white minis, one cut under water and the other not and put them each in blue floral dye. The bunch which was cut under water had uniformly absorbed the dye and was gorgeous, and the other was all blotchy. They were passed around, and everyone in the audience was amazed. I didn't really need any convincing, since I have never had any problems with flowers drinking since I've been doing it - but it did reassure me that my extra efforts hadn't been in vain.