How to grow tulip bulbs in a vase. Fill water in the vase to just under the bottom of the bulbs. You do not want the water to touch the base of the bulbs. Place in a room with bright, indirect sunlight and watch the bulbs grow! Roots will work their way down through the glass beads into the water.
I like this it came from http://www.vegetablegardener.com/item/12278/5-great-reasons-to-grow-vegetables-vertically. I could not find instructions, however a close look at the unit shows burlap or something similar holding the dirt, and moisture, and that seems to be it. Even if you just used it to hold small pots of herbs, it's still a good idea for small space gardening.