Martha Stewart Kids, Winter 2006
Watch plants grow before your eyes with a bookshelf terrarium. Cover the bottom of a jar with gravel, then add 1/4 inch of ground charcoal. Mix 2 parts potting soil, 2 parts peat, and 1 part builder's sand; add to jar. Dig small holes for plants, such as sweet flag or Chinese elm. Spray completely with water before putting on lid.
The terrarium should retain moisture, so rewatering won't be necessary, but you should check the soil periodically to be safe.
what other plants could i use? any ideas?