When and how you harvest flowers grown in your garden will determine how well the blooms keep in storage for the bouquet you intend to make at a later time. Harvest your homegrown blossoms, using sharp blade pruners, in the early morning when the stems are fully hydrated. Immediately place the stems in a container that has cool water in it. When you bring the fresh cut flowers indoors, prepare them for storing by first using a method termed "hardening." Mix commercial floral preservative according to the directions in water that is 110 degrees F. Place your freshly cut flower stems into this hot water mixture for one to two hours while the container and blooms are stored in a cool location. The principal behind this method is that hot water is rapidly drawn up the stem of the flower, fully hydrating the blossom, leaves and stem to its capacity. When you cut a flower from a plant, you take away the flower's food source, so the more you can replace the food the better and longer your flowers will last.
After you have hardened your fresh cut flowers, transfer them to a container of lukewarm water with floral preservative for storage. Place this container in a location that is cool, 65 degrees F or lower, away from sunlight and drafts.
When you purchase fresh flowers from a florist or commercial grower for use in a later bouquet, the blooms will probably come bundled in a cellophane wrapper and may have a rubber band around the stems. Remove the rubber band, but keep the cellophane wrapper around the flowers to help keep the flower heads from possibly drooping while stored. After you have removed the rubber band, cut a small amount of the stem off, 1/2 inch or so. Like homegrown flowers, harden the flowers by placing the stems in a water and floral preservative mix that is at 110 degrees F. Leave the flowers in the hot water for one to two hours so they may drink up as much fluid as possible and become fully hydrated. To store commercially grown flowers for a bouquet made later, place the flowers in a container that has a water and floral preservative. Put the container with the flowers in a cool location, 65 degrees F or cooler, but not below 35 degrees F. The location should be away from direct sunlight, drafts and heat sources.
When you cut the ends of the stems, cut them at an angle to open a larger area for the stem to take up water. The stems should be recut every time you change water or containers. Fresh water is a key ingredient to successfully keeping fresh cut flowers fresh. Change the water in the container your stored flowers are in daily. Lukewater or cool water, with floral preservative, is the best for maintaining freshness.