Delicate hibiscus flowers require special handling during and after preservation. The blossoms are fragile and can't tolerate the pressure from conventional flower pressing. The use of a desiccant wicks the moisture from the hibiscus petals while still protecting the shape and color of the bloom. Silica crystals provide optimum drying as they are designed to wick away moisture without creating a damp environment. Once preserved, the hibiscus requires gentle handling so the papery flowers don't shatter.
Fill a plastic container with a 1-inch layer of silica crystals. Use a container that is 4 to 5 inches deep and only slightly wider than the blossom.
Trim the stem of the hibiscus to a 1/2-inch length. Choose flowers at the height of their blooming that have no damaged or discolored petals.
Set the flower face-up on top of the layer of silica. Press the flower lightly into the silica so the crystals support the petals.
Sprinkle silica crystals on top of the flower. Cover the flower completely with a 1-inch deep layer of silica.
Place the lid on the container and seal it closed. Place it in an area where it won't be disturbed for several weeks, as shifting the container during drying may result in a broken or wrinkled flower.
Dry the hibiscus in the silica for three weeks. Remove the lid from the container and pour off the crystals from the top of the flower. Lift the flower gently from the container and brush off any remaining silica.