Dry flowers by covering the flower blooms completely with drying agents, such as borax or white cornmeal, for up to a week. Drying agents are most often used to dry flowers with thick heads, such as roses, marigolds, dahlias and delphinium.
Other drying agents used to dry out flowers include rice and silica gel, because they keep the flower bloom intake and vibrant while leaching out the moisture. To dry a flower, pour some of the drying agent into the bottom of a plastic container, place the flower blossom down on the agent, and cover up the rest of the flower with the remaining drying agent. Place an airtight lid on the container, and store it in a dark location. After one week, check the flower to see if it is dried out.
Remove the drying agent from the flower carefully to keep from damaging the crisp petals. Help the flower to keep from crumbling by spraying it with hairspray. If you are not immediately going to use the dried flowers, put them in an airtight container with a little of the drying agent to keep the flowers moisture-free. Flowers can be dried more quickly if they are placed in a glass container with silica gel and microwaved for up to three minutes.