Silica gel is not a gel at all. It looks like white sand with blue crystals. One can purchase canisters of Silica Gel Flower Drying Crystals at craft stores.

The method of drying with silica is rather expensive, time consuming and absolutely gorgeous. (See method below for a less expensive alternative).

If you need enough dried hydrangeas for an arrangement or a wreath, dry about twice as many as you think you will need. This is not because some of the blooms will dry poorly, but because one can never believe how many it will take to make a nice, full arrangement. Also, to fill out the design, consider including small, naturally dried hydrangeas in with the silica dried hydrangeas.

STEPS IN DRYING WITH SILICA GEL:
The method of drying hydrangeas with silica gel will result in vivid colours and an amazingly natural appearance. While this process is very simple, it must be pursued over a number of weeks to obtain enough dried flower heads to make an arrangement.

1. Use plastic Tupperware-type containers that are large enough to hold flowers without crushing them.
2. Cut fresh, recently opened hydrangeas from the shrub on the morning of the day they are to be put into the silica.
3. Cut stems very short so they will fit in containers.
4. Place hydrangea head in the container on a thin layer of silica gel. (Experiment with stem being up or down.) Gradually sift silica around the head, working it into the center and under all petals. When the first bloom is covered, continue to layer whole or parts of flower heads with silica gel to within a ½ inch of the container lid. Do not force them to fit in the container, or they will be unnaturally shaped.
5. Secure lid on container and label with date.
6. Four days later pour contents very slowly onto newspaper and pluck out hydrangeas.
7. Gently tap them clean and place in plastic bags for storage until ready for use.
8. Do not leave hydrangeas in silica for more than four days, or they will be too brittle (unless silica is more than 2-3 years old).
9. To lengthen a stem that has been cut short, tape a dry stem to hydrangea with florist tape. This is not necessary for a wreath.