Floral preservative will also help. If possible, remove the stems from the vase and re-cut every few days for an even longer life. This is not possible on most arrangements. Keep fresh flowers cool. When they are not being viewed store them in the coolest room of the home or office.
Cool temperatures slow down the aging process.
Also keep the cut flowers out of sunny areas or hot drafts. With good care most cut flowers will last about a week to ten days. Although not as popular as fresh flowers, potted plants make a great gift. They do not seem to have the same sex appeal but the blooms will last longer, even up to three to five weeks depending on the type. Keep potted flowering plants moist, but do not allow the roots to sit in water.