Gardenias are a very popular shrub with gardeners because of their large, beautiful and fragrant blooms. They are grown outdoors in warm, humid climates with plenty of sunlight, but they can be grown indoors as houseplants in the absence of those conditions. You can start your own gardenia plant with just a clipping from another healthy one.
Cut a 4-6 inch long stem -- the growing tip of any branch -- from a healthy gardenia shrub. Remove the leaves from the lower part of the stem, but leave a couple of sets of leaves toward the top of the stem.
Fold a paper towel multiple times so that it is long and narrow (about 1 inch wide). Set the stem on one end of the paper towel, with the stem running perpendicular to the length of it. Place the stem so that about half of its length is on each side of the paper towel.
Roll the stem up in the paper towel. You should end up with a paper towel band around the midpoint of the stem.
Fill a clean glass soda bottle with water that is at room temperature. Place the stripped end of the stem in the bottle, and use the paper towel band to "cork" the bottle.
Place the bottle where it will receive filtered light and gentle warmth. Too much and the gardenia will not take root. Keep the bottle full of fresh water. Look for small, white roots growing from the cutting after a few weeks. Transplant the cutting into a pot and potting soil after two to three more weeks of root growth.