Cut a stem (or stems, if you want to propagate multiple new rose plants) from a rose bush. The bush should be healthy and free from disease and parasites, so check the bush before taking your cuttings. The cuttings should measure about 6 inches in length.
Remove the lower set of leaves from each of the cuttings you just took from the original rose plant.
Place each cutting into the soil in your garden, or in a 10-inch flowerpot. Make sure the cutting is facing in the right direction (the top of the leaves should be facing up, while the bottom of the leaves should face the soil). Push 2 to 3 inches of the cutting into the soil, leaving the remaining portion above the soil.
Place the 1-quart jar or 2-liter bottle over each cutting (the soda bottle should have the cap still on so that no air enters or exits the jar).
Water the soil around each cutting every few days or when the soil looks dry. This will prevent your cuttings from drying out.
Continue to care for each rose cutting with the jar or bottle covering it until you see new leaves on the stems. This typically takes four to eight weeks.
If you have placed the cuttings directly in the garden, you can simply remove the jar or bottle, leaving the new plant where it is. If you have placed the cuttings in a pot, you can choose to transplant the new plant to the garden after removing the jar or bottle, or allow it to continue to grow in a container.