6 tbsp. salt
6 tbsp. water
6 tbsp. laundry bluing (in laundry dept. at grocery store)
1 tbsp. ammonia
5 or 6 pieces charcoal
Food coloring
A glass container

Adult supervision is needed with ammonia!

Mix salt, water, bluing and ammonia in a large bowl.

Put charcoal in an old glass bowl. Pour mixture over charcoal. Sprinkle drops of food coloring for color. Set container in a warm place and do not move it. It will continue to grow crystals until all liquid is absorbed. (You can make several small gardens in glass jars, dividing the liquid over them.)