How to Grow a Salt Crystal Garden

These crystals were grown from a mixture of laundry bluing, ammonia and salt.
These crystals were grown from a mixture of equal parts Mrs. Stewart's Laundry Bluing (which is Prussian blue or iron(III) ferrocyanide), ammonia and salt. Anne Helmenstine

A salt crystal garden produces a tree of white or colored crystals. Learn how to grow a salt crystal garden using a paper towel or toilet paper tube and a salt crystal solution.

Salt Crystal Garden Materials

  • toilet paper tube or about 4" of a paper towel tube
  • 3 tablespoons household ammonia
  • 3 tablespoons iron(III) ferrocyanide solution
  • 1 tablespoon table salt

The iron(III) ferrocyanide solution may be made by suspending the powdered chemical in water or you may use Prussian Blue artist pigment, diluted to produce a deep blue-colored liquid, or you can use Mrs. Stewart's Laundry Bluing (find online).

Grow a Salt Crystal Garden

  1. Stir the salt crystal ingredients together in the bottom of a shallow dish.
  2. Set the paper tube in the center of the dish. If you like, you can cut the tube to resemble a tree. The salt crystals will be white, so if you want colored crystals, dot the paper tube with food coloring or color it with a water-soluble marker.
  3. Place the salt crystal garden somewhere it won't be bumped or disturbed. Over the course of a few hours, the liquid will move up the tube and start growing crystals. Crystals will continue to grow for a day or more or you can add more solution if you want to continue crystal growth for a week or two.