Cordyline australis, also known as purple tower plant or cabbage palm, is a colourful palmlike plant available in shades of red, purple or green, with contrasting veins that mark the sword-shaped leaves. If you live in the warm, tropical climates of U.S. Department of Agriculture hardiness zones 10b or 11, you can plant Cordyline australis outdoors. Otherwise, grow the plant in a pot as an indoor plant or bring the plant indoors for the winter.
Use a sharp knife or pruning shears to cut a length of stem from the tip of a healthy Cordyline australis plant. The stem should be long enough to have at least one healthy leaf at the tip, with 3 to 4 inches of bare stem beneath the leaf. If necessary, remove the lower leaves to reveal bare stem.
Fill a 4-inch pot with a well-drained potting mixture such as a combination of half coarse sand and half perlite or vermiculite. Moisten the potting mixture by placing the pot in a saucer or shallow bowl filled with water. Allow the potting mixture to absorb water through the drainage hole until the potting mixture is wet through. Set the pot aside to drain for several hours, as the potting mixture should be evenly moist but not dripping.
Dip the cut end of the Cordyline australis cutting in powdered rooting hormone, then plant the cutting in the potting mixture. Firm the potting mixture firmly around the stem so the cutting will remain upright. Don't allow the leaves to touch the soil, as doing so may cause the stem to rot.
Cover the pot loosely with a clear plastic bag to maintain a moist atmosphere for the cutting. Don't secure the bag, as the Cordyline australis cutting requires adequate ventilation. Place the cutting in bright, indirect light in a room with temperatures about 21.1 degrees Celsius. Keep the potting mixture slightly moist. Rooting can take a few days or a few weeks.
Dig up the Cordyline australis carefully with a spoon. If the roots are less than an inch in length, carefully replant the cutting. If the stem is a minimum of 1 inch in length, move the cutting to a 6-inch pot filled with any general purpose potting mix.
Allow the new Cordyline australis plant to remain in indirect light for about a week, then move the plant into bright sunlight. Keep the soil lightly moist until new growth appears. After that time, water only when the soil feels slightly dry. Water the plant deeply so that water runs through the drainage hole, then let the pot drain for five to 10 minutes before returning the pot to its drainage saucer.