Propagating roses from stem cuttings is the easiest and least expensive way to start a new rose bush, and the success rate is very high. It's especially useful if you want to reproduce a favorite rose or an heirloom plant. Although there are several steps involved, the process is really quite simple, and the cutting should take root in about a month.
Choose a stem from a healthy rose bush. A stem that has a rose that has just finished blooming is best, but don't choose a stem with a bud. Be sure the stem has at least three sets of leaves.
Use a clean, sharp knife to cut the stem at an angle just below a leaf node, which is a bump where a leaf is about to emerge. Remove any blooms or buds from the stem, and snip off the lower sets of leaves from the cut end.
Put an inch of sand on the bottom of the planting container, and then fill it with good quality commercial potting soil. Any container will work, as long as it has drainage holes in the bottom.
Dip at least 2 inches of the lower stem into rooting hormone. Place the stem in the planting container, pushing it in far enough so the cut end will be in the sand, and tamp the soil down lightly. Be sure the leaves are above the soil.
Put the container in a clear plastic bag and seal the bag. Put the container in a warm place out of direct sunlight. The plastic bag will keep the environment humid, but if the soil appears dry, remove the bag, mist the soil and replace the bag.
Check in 3 to 4 weeks to see if the stem cutting has taken root. You can tell by tugging lightly on the cutting; if there is resistance, the cutting has rooted. You'll also be able to tell by looking for tiny white roots coming through the drainage hole in the bottom of the pot.
Remove the plastic when the cutting has taken root. Keep the cutting in a warm, well-lit place and keep the soil moist until you're ready to plant the new rose bush outside.