While some plants may be rooted by placing a stem in a glass of water, azalea isn't one of them. Although azalea can be propagated by a variety of methods, azalea, like most woody plants, needs soil in order to develop roots.
Evergreen azaleas are often propagated by taking stem cuttings from established plants. The cuttings are planted in a moist planting medium, then placed in a greenhouse. In mild, humid climates, cuttings are placed outdoors. Azalea stem cuttings usually root in four to six weeks.
Deciduous azaleas and varieties that may be difficult to grow by other methods are often propagated by seed. The seeds are planted in a container or planting tray filled with damp sphagnum moss, with the seeds scattered on top of the moss. The container is covered with clear plastic before being placed in indirect light. Germination usually occurs within a month.
Although layering is a simple way to propagate azaleas, the process is slow. A long, low branch is bent to the ground. The bark is scraped at the point where the branch touches the ground. The scraped branch is then secured to the ground with a piece of wire. In about a year, the branch is rooted and can be cut from the parent plant.