At this time of year, when there are many flowers blooming in our gardens, it's easier than at other times of the year to pick bouquets for our own homes and as gifts for friends. To ensure that cut flowers last in a vase it helps to condition them.
Before arranging them, cut the stems on a slant. This allows more cells to absorb water and prevents the stems from resting flat against the base of a container, which hampers water absorption. Scissors squeeze the stem, so once the flowers come inside take a sharp knife to re-cut the stems. It's helpful to cut flowers in the early evening, and then they can stand in warm water overnight, as it is reputed to move up the stems more quickly than cold water.
Once re-cut and placed in warm (not hot) water, leave the container of blooms overnight in a cool dark place to reduce stress and loss of moisture.
Then the next day before they are arranged, cut another inch from the base of each individual stem using a diagonal cut with a knife. Always remove any leaves that would be below the water line, as they rot and contaminate the water; even flowers that have been purchased benefit from re-cutting and conditioning before they are arranged.
Conditioning really does extend the life of cut flowers so it's worth the effort.